Cisco Systems Cat2960-Xr User Manual

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Catalyst 2960 Switch Software Configuration Guide

Cisco IOS Release 12.2(25)FX September 2005

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Catalyst 2960 Switch Software Configuration Guide

Preface xxvii

Audience xxvii

Purpose xxvii

Conventions xxviii

Related Publications xxviii

Obtaining Documentation xxix

Cisco.com xxix Product Documentation DVD xxx Ordering Documentation xxx

Documentation Feedback xxx

Cisco Product Security Overview xxxi

Reporting Security Problems in Cisco Products xxxi

CHAPTER

Obtaining Technical Assistance xxxii

Cisco Technical Support & Documentation Website xxxii Submitting a Service Request xxxii Definitions of Service Request Severity xxxiii

Obtaining Additional Publications and Information xxxiii

1 Overview 1-1

Features 1-1

Ease-of-Use and Ease-of-Deployment Features 1-2 Performance Features 1-3 Management Options 1-3 Manageability Features 1-4 Availability Features 1-5 VLAN Features 1-6 Security Features 1-6 QoS and CoS Features 1-7 Monitoring Features 1-8

Default Settings After Initial Switch Configuration 1-8

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Network Configuration Examples 1-11

Design Concepts for Using the Switch 1-11 Small to Medium-Sized Network Using Catalyst 2960 Switches 1-14 Long-Distance, High-Bandwidth Transport Configuration 1-15

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Contents

Where to Go Next 1-16

CHAPTER

2 Using the Command-Line Interface 2-1

Understanding Command Modes 2-1

Understanding the Help System 2-3

Understanding Abbreviated Commands 2-4

Understanding no and default Forms of Commands 2-4

Understanding CLI Error Messages 2-5

Using Command History 2-5

Changing the Command History Buffer Size 2-5 Recalling Commands 2-6 Disabling the Command History Feature 2-6

Using Editing Features 2-6

Enabling and Disabling Editing Features 2-7 Editing Commands through Keystrokes 2-7 Editing Command Lines that Wrap 2-8

Searching and Filtering Output of show and more Commands 2-9

Accessing the CLI 2-9

Accessing the CLI through a Console Connection or through Telnet 2-10

CHAPTER

3 Assigning the Switch IP Address and Default Gateway 3-1

Understanding the Boot Process 3-1

Assigning Switch Information 3-2

Default Switch Information 3-3 Understanding DHCP-Based Autoconfiguration 3-3

DHCP Client Request Process 3-4

Configuring DHCP-Based Autoconfiguration 3-5

DHCP Server Configuration Guidelines 3-5 Configuring the TFTP Server 3-5 Configuring the DNS 3-6 Configuring the Relay Device 3-6 Obtaining Configuration Files 3-7 Example Configuration 3-8

Manually Assigning IP Information 3-9

Checking and Saving the Running Configuration 3-10

Modifying the Startup Configuration 3-11

Default Boot Configuration 3-12 Automatically Downloading a Configuration File 3-12

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Specifying the Filename to Read and Write the System Configuration 3-12 Booting Manually 3-13 Booting a Specific Software Image 3-13 Controlling Environment Variables 3-14

Scheduling a Reload of the Software Image 3-15

Configuring a Scheduled Reload 3-16 Displaying Scheduled Reload Information 3-17

Contents

CHAPTER

4 Configuring IE2100 CNS Agents 4-1

Understanding IE2100 Series Configuration Registrar Software 4-1

CNS Configuration Service 4-2 CNS Event Service 4-3

NameSpace Mapper 4-3

What You Should Know About ConfigID, DeviceID, and Hostname 4-3

ConfigID 4-3 DeviceID 4-4 Hostname and DeviceID 4-4 Using Hostname, DeviceID, and ConfigID 4-4

Understanding CNS Embedded Agents 4-5

Initial Configuration 4-5 Incremental (Partial) Configuration 4-6 Synchronized Configuration 4-6

Configuring CNS Embedded Agents 4-6

Enabling Automated CNS Configuration 4-6 Enabling the CNS Event Agent 4-8 Enabling the CNS Configuration Agent 4-9

Enabling an Initial Configuration 4-9 Enabling a Partial Configuration 4-12

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Displaying CNS Configuration 4-13

5 Clustering Switches 5-1

Understanding Switch Clusters 5-1

Clustering Overview 5-1 Cluster Command Switch Characteristics 5-2 Standby Cluster Command Switch Characteristics 5-2 Candidate Switch and Cluster Member Switch Characteristics 5-3

Using the CLI to Manage Switch Clusters 5-3

Catalyst 1900 and Catalyst 2820 CLI Considerations 5-4

Using SNMP to Manage Switch Clusters 5-4

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CHAPTER

6 Administering the Switch 6-1

Managing the System Time and Date 6-1

Understanding the System Clock 6-2 Understanding Network Time Protocol 6-2 Configuring NTP 6-4

Default NTP Configuration 6-4 Configuring NTP Authentication 6-5 Configuring NTP Associations 6-6 Configuring NTP Broadcast Service 6-7 Configuring NTP Access Restrictions 6-8 Configuring the Source IP Address for NTP Packets 6-10 Displaying the NTP Configuration 6-11

Configuring Time and Date Manually 6-11

Setting the System Clock 6-11 Displaying the Time and Date Configuration 6-12 Configuring the Time Zone 6-12 Configuring Summer Time (Daylight Saving Time) 6-13

Configuring a System Name and Prompt 6-14

Default System Name and Prompt Configuration 6-15 Configuring a System Name 6-15 Understanding DNS 6-15

Default DNS Configuration 6-16 Setting Up DNS 6-16 Displaying the DNS Configuration 6-17

Creating a Banner 6-17

Default Banner Configuration 6-17 Configuring a Message-of-the-Day Login Banner 6-18 Configuring a Login Banner 6-18

Managing the MAC Address Table 6-19

Building the Address Table 6-20 MAC Addresses and VLANs 6-20 Default MAC Address Table Configuration 6-20 Changing the Address Aging Time 6-21 Removing Dynamic Address Entries 6-21 Configuring MAC Address Notification Traps 6-21 Adding and Removing Static Address Entries 6-23 Configuring Unicast MAC Address Filtering 6-24 Displaying Address Table Entries 6-25

Managing the ARP Table 6-26

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Contents

CHAPTER

7 Configuring SDM Templates 7-1

Understanding the SDM Templates 7-1

Configuring the Switch SDM Template 7-2

Default SDM Template 7-2 SDM Template Configuration Guidelines 7-2 Setting the SDM Template 7-2

Displaying the SDM Templates 7-3

8 Configuring Switch-Based Authentication 8-1

Preventing Unauthorized Access to Your Switch 8-1

Protecting Access to Privileged EXEC Commands 8-2

Default Password and Privilege Level Configuration 8-2 Setting or Changing a Static Enable Password 8-3 Protecting Enable and Enable Secret Passwords with Encryption 8-3 Disabling Password Recovery 8-5 Setting a Telnet Password for a Terminal Line 8-6 Configuring Username and Password Pairs 8-7 Configuring Multiple Privilege Levels 8-8

Setting the Privilege Level for a Command 8-8 Changing the Default Privilege Level for Lines 8-9 Logging into and Exiting a Privilege Level 8-10

Controlling Switch Access with TACACS+ 8-10

Understanding TACACS+ 8-10 TACACS+ Operation 8-12 Configuring TACACS+ 8-12

Default TACACS+ Configuration 8-13 Identifying the TACACS+ Server Host and Setting the Authentication Key 8-13 Configuring TACACS+ Login Authentication 8-14 Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 8-16 Starting TACACS+ Accounting 8-17

Displaying the TACACS+ Configuration 8-17

Controlling Switch Access with RADIUS 8-17

Understanding RADIUS 8-18 RADIUS Operation 8-19 Configuring RADIUS 8-20

Default RADIUS Configuration 8-20 Identifying the RADIUS Server Host 8-20 Configuring RADIUS Login Authentication 8-23 Defining AAA Server Groups 8-25

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Configuring RADIUS Authorization for User Privileged Access and Network Services 8-27 Starting RADIUS Accounting 8-28 Configuring Settings for All RADIUS Servers 8-29 Configuring the Switch to Use Vendor-Specific RADIUS Attributes 8-29 Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 8-30

Displaying the RADIUS Configuration 8-31

Configuring the Switch for Local Authentication and Authorization 8-32

Configuring the Switch for Secure Shell 8-33

Understanding SSH 8-33

SSH Servers, Integrated Clients, and Supported Versions 8-33 Limitations 8-34

Configuring SSH 8-34

Configuration Guidelines 8-34 Setting Up the Switch to Run SSH 8-35 Configuring the SSH Server 8-36

Displaying the SSH Configuration and Status 8-36

CHAPTER

Configuring the Switch for Secure Socket Layer HTTP 8-37

Understanding Secure HTTP Servers and Clients 8-37

Certificate Authority Trustpoints 8-37 CipherSuites 8-39

Configuring Secure HTTP Servers and Clients 8-39

Default SSL Configuration 8-39 SSL Configuration Guidelines 8-40 Configuring a CA Trustpoint 8-40 Configuring the Secure HTTP Server 8-41 Configuring the Secure HTTP Client 8-42

Displaying Secure HTTP Server and Client Status 8-43

9 Configuring IEEE 802.1x Port-Based Authentication 9-1

Understanding IEEE 802.1x Port-Based Authentication 9-1

Device Roles 9-2 Authentication Initiation and Message Exchange 9-3 Ports in Authorized and Unauthorized States 9-4 IEEE 802.1x Accounting 9-5 IEEE 802.1x Accounting Attribute-Value Pairs 9-5 IEEE 802.1x Host Mode 9-6 Using IEEE 802.1x with Port Security 9-7 Using IEEE 802.1x with Voice VLAN Ports 9-8

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Using IEEE 802.1x with VLAN Assignment 9-8 Using IEEE 802.1x with Guest VLAN 9-10

Configuring IEEE 802.1x Authentication 9-10

Default IEEE 802.1x Configuration 9-11 IEEE 802.1x Configuration Guidelines 9-12 Configuring IEEE 802.1x Authentication 9-12 Configuring the Switch-to-RADIUS-Server Communication 9-14 Configuring Periodic Re-Authentication 9-15 Manually Re-Authenticating a Client Connected to a Port 9-15 Changing the Quiet Period 9-16 Changing the Switch-to-Client Retransmission Time 9-16 Setting the Switch-to-Client Frame-Retransmission Number 9-17 Setting the Re-Authentication Number 9-17 Configuring the Host Mode 9-18 Configuring a Guest VLAN 9-19 Resetting the IEEE 802.1x Configuration to the Default Values 9-20 Configuring IEEE 802.1x Accounting 9-21

Contents

CHAPTER

Displaying IEEE 802.1x Statistics and Status 9-22

10 Configuring Interface Characteristics 10-1

Understanding Interface Types 10-1

Port-Based VLANs 10-2 Switch Ports 10-2

Access Ports 10-2

Trunk Ports 10-3 EtherChannel Port Groups 10-3 Dual-Purpose Uplink Ports 10-4 Connecting Interfaces 10-4

Using Interface Configuration Mode 10-4

Procedures for Configuring Interfaces 10-5 Configuring a Range of Interfaces 10-6 Configuring and Using Interface Range Macros 10-7

Configuring Ethernet Interfaces 10-9

Default Ethernet Interface Configuration 10-9 Configuring Interface Speed and Duplex Mode 10-10

Speed and Duplex Configuration Guidelines 10-11

Setting the Type of a Dual-Purpose Uplink Port 10-11

Setting the Interface Speed and Duplex Parameters 10-13

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Configuring IEEE 802.3x Flow Control 10-14 Configuring Auto-MDIX on an Interface 10-15 Adding a Description for an Interface 10-16

Configuring the System MTU 10-16

Monitoring and Maintaining the Interfaces 10-18

Monitoring Interface Status 10-18 Clearing and Resetting Interfaces and Counters 10-19 Shutting Down and Restarting the Interface 10-19

CHAPTER

11 Configuring Smartports Macros 11-1

Understanding Smartports Macros 11-1

Configuring Smartports Macros 11-2

Default Smartports Macro Configuration 11-2 Smartports Macro Configuration Guidelines 11-3 Creating Smartports Macros 11-4 Applying Smartports Macros 11-5 Applying Cisco-Default Smartports Macros 11-6

Displaying Smartports Macros 11-8

12 Configuring VLANs 12-1

Understanding VLANs 12-1

Supported VLANs 12-2 VLAN Port Membership Modes 12-3

Configuring Normal-Range VLANs 12-4

Token Ring VLANs 12-5 Normal-Range VLAN Configuration Guidelines 12-5 VLAN Configuration Mode Options 12-6

VLAN Configuration in config-vlan Mode 12-6

VLAN Configuration in VLAN Database Configuration Mode 12-6 Saving VLAN Configuration 12-6 Default Ethernet VLAN Configuration 12-7 Creating or Modifying an Ethernet VLAN 12-8 Deleting a VLAN 12-9 Assigning Static-Access Ports to a VLAN 12-10

Configuring Extended-Range VLANs 12-11

Default VLAN Configuration 12-11 Extended-Range VLAN Configuration Guidelines 12-12 Creating an Extended-Range VLAN 12-12

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Displaying VLANs 12-13

Configuring VLAN Trunks 12-14

Trunking Overview 12-14

IEEE 802.1Q Configuration Considerations 12-15 Default Layer 2 Ethernet Interface VLAN Configuration 12-16 Configuring an Ethernet Interface as a Trunk Port 12-16

Interaction with Other Features 12-16

Configuring a Trunk Port 12-17

Defining the Allowed VLANs on a Trunk 12-18

Changing the Pruning-Eligible List 12-19

Configuring the Native VLAN for Untagged Traffic 12-19 Configuring Trunk Ports for Load Sharing 12-20

Load Sharing Using STP Port Priorities 12-20

Load Sharing Using STP Path Cost 12-22

Configuring VMPS 12-23

Understanding VMPS 12-24

Dynamic-Access Port VLAN Membership 12-24 Default VMPS Client Configuration 12-25 VMPS Configuration Guidelines 12-25 Configuring the VMPS Client 12-26

Entering the IP Address of the VMPS 12-26

Configuring Dynamic-Access Ports on VMPS Clients 12-26

Reconfirming VLAN Memberships 12-27

Changing the Reconfirmation Interval 12-27

Changing the Retry Count 12-28 Monitoring the VMPS 12-28 Troubleshooting Dynamic-Access Port VLAN Membership 12-29 VMPS Configuration Example 12-29

Contents

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13 Configuring VTP 13-1

Understanding VTP 13-1

The VTP Domain 13-2 VTP Modes 13-3 VTP Advertisements 13-3 VTP Version 2 13-4 VTP Pruning 13-4

Configuring VTP 13-6

Default VTP Configuration 13-6 VTP Configuration Options 13-7

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VTP Configuration in Global Configuration Mode 13-7 VTP Configuration in VLAN Database Configuration Mode 13-7

VTP Configuration Guidelines 13-8

Domain Names 13-8 Passwords 13-8 VTP Version 13-8

Configuration Requirements 13-9 Configuring a VTP Server 13-9 Configuring a VTP Client 13-11 Disabling VTP (VTP Transparent Mode) 13-12 Enabling VTP Version 2 13-13 Enabling VTP Pruning 13-14 Adding a VTP Client Switch to a VTP Domain 13-14

Monitoring VTP 13-16

CHAPTER

14 Configuring Voice VLAN 14-1

Understanding Voice VLAN 14-1

Cisco IP Phone Voice Traffic 14-2 Cisco IP Phone Data Traffic 14-2

Configuring Voice VLAN 14-3

Default Voice VLAN Configuration 14-3 Voice VLAN Configuration Guidelines 14-3 Configuring a Port Connected to a Cisco 7960 IP Phone 14-4

Configuring IP Phone Voice Traffic 14-5

Configuring the Priority of Incoming Data Frames 14-6

Displaying Voice VLAN 14-6

15 Configuring STP 15-1

Understanding Spanning-Tree Features 15-1

STP Overview 15-2 Spanning-Tree Topology and BPDUs 15-3 Bridge ID, Switch Priority, and Extended System ID 15-4 Spanning-Tree Interface States 15-4

Blocking State 15-6

Listening State 15-6

Learning State 15-6

Forwarding State 15-6

Disabled State 15-7

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How a Switch or Port Becomes the Root Switch or Root Port 15-7 Spanning Tree and Redundant Connectivity 15-8 Spanning-Tree Address Management 15-8 Accelerated Aging to Retain Connectivity 15-8 Spanning-Tree Modes and Protocols 15-9 Supported Spanning-Tree Instances 15-9 Spanning-Tree Interoperability and Backward Compatibility 15-10 STP and IEEE 802.1Q Trunks 15-10

Configuring Spanning-Tree Features 15-10

Default Spanning-Tree Configuration 15-11 Spanning-Tree Configuration Guidelines 15-11 Changing the Spanning-Tree Mode. 15-12 Disabling Spanning Tree 15-13 Configuring the Root Switch 15-14 Configuring a Secondary Root Switch 15-15 Configuring Port Priority 15-16 Configuring Path Cost 15-17 Configuring the Switch Priority of a VLAN 15-19 Configuring Spanning-Tree Timers 15-19

Configuring the Hello Time 15-20 Configuring the Forwarding-Delay Time for a VLAN 15-21 Configuring the Maximum-Aging Time for a VLAN 15-21

Contents

CHAPTER

Displaying the Spanning-Tree Status 15-22

16 Configuring MSTP 16-1

Understanding MSTP 16-2

Multiple Spanning-Tree Regions 16-2 IST, CIST, and CST 16-3

Operations Within an MST Region 16-3

Operations Between MST Regions 16-4 Hop Count 16-5 Boundary Ports 16-5 Interoperability with IEEE 802.1D STP 16-5

Understanding RSTP 16-6

Port Roles and the Active Topology 16-6 Rapid Convergence 16-7 Synchronization of Port Roles 16-8

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Bridge Protocol Data Unit Format and Processing 16-9

Processing Superior BPDU Information 16-10 Processing Inferior BPDU Information 16-10

Topology Changes 16-10

Configuring MSTP Features 16-11

Default MSTP Configuration 16-11 MSTP Configuration Guidelines 16-12 Specifying the MST Region Configuration and Enabling MSTP 16-13 Configuring the Root Switch 16-14 Configuring a Secondary Root Switch 16-15 Configuring Port Priority 16-16 Configuring Path Cost 16-17 Configuring the Switch Priority 16-18 Configuring the Hello Time 16-19 Configuring the Forwarding-Delay Time 16-20 Configuring the Maximum-Aging Time 16-20 Configuring the Maximum-Hop Count 16-21 Specifying the Link Type to Ensure Rapid Transitions 16-21 Restarting the Protocol Migration Process 16-22

CHAPTER

Displaying the MST Configuration and Status 16-22

17 Configuring Optional Spanning-Tree Features 17-1

Understanding Optional Spanning-Tree Features 17-1

Understanding Port Fast 17-2 Understanding BPDU Guard 17-3 Understanding BPDU Filtering 17-3 Understanding UplinkFast 17-4 Understanding BackboneFast 17-5 Understanding EtherChannel Guard 17-7 Understanding Root Guard 17-8 Understanding Loop Guard 17-9

Configuring Optional Spanning-Tree Features 17-9

Default Optional Spanning-Tree Configuration 17-9 Optional Spanning-Tree Configuration Guidelines 17-10 Enabling Port Fast 17-10 Enabling BPDU Guard 17-11 Enabling BPDU Filtering 17-12 Enabling UplinkFast for Use with Redundant Links 17-13 Enabling BackboneFast 17-14

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Enabling EtherChannel Guard 17-14 Enabling Root Guard 17-15 Enabling Loop Guard 17-15

Displaying the Spanning-Tree Status 17-16

Contents

CHAPTER

18 Configuring Flex Links 18-1

Understanding Flex Links 18-1

Configuring Flex Links 18-2

Default Flex Link Configuration 18-2 Flex Link Configuration Guidelines 18-2 Configuring Flex Links 18-3

Monitoring Flex Links 18-3

19 Configuring DHCP Features 19-1

Understanding DHCP Features 19-1

DHCP Server 19-2 DHCP Relay Agent 19-2 DHCP Snooping 19-2 Option-82 Data Insertion 19-3 DHCP Snooping Binding Database 19-5

Configuring DHCP Features 19-6

Default DHCP Configuration 19-7 DHCP Snooping Configuration Guidelines 19-7 Configuring the DHCP Relay Agent 19-8 Enabling DHCP Snooping and Option 82 19-9 Enabling the DHCP Snooping Binding Database Agent 19-10

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Displaying DHCP Snooping Information 19-11

20 Configuring IGMP Snooping and MVR 20-1

Understanding IGMP Snooping 20-1

IGMP Versions 20-2 Joining a Multicast Group 20-3 Leaving a Multicast Group 20-4 Immediate Leave 20-5 IGMP Configurable-Leave Timer 20-5 IGMP Report Suppression 20-5

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Configuring IGMP Snooping 20-6

Default IGMP Snooping Configuration 20-6 Enabling or Disabling IGMP Snooping 20-6 Setting the Snooping Method 20-7 Configuring a Multicast Router Port 20-8 Configuring a Host Statically to Join a Group 20-9 Enabling IGMP Immediate Leave 20-9 Configuring the IGMP Leave Timer 20-10 Configuring TCN-Related Commands 20-11

Controlling the Multicast Flooding Time After a TCN Event 20-11 Recovering from Flood Mode 20-12

Disabling Multicast Flooding During a TCN Event 20-12 Configuring the IGMP Snooping Querier 20-13 Disabling IGMP Report Suppression 20-14

Displaying IGMP Snooping Information 20-14

CHAPTER

Understanding Multicast VLAN Registration 20-16

Using MVR in a Multicast Television Application 20-16

Configuring MVR 20-18

Default MVR Configuration 20-18 MVR Configuration Guidelines and Limitations 20-18 Configuring MVR Global Parameters 20-19 Configuring MVR Interfaces 20-20

Displaying MVR Information 20-21

Configuring IGMP Filtering and Throttling 20-22

Default IGMP Filtering and Throttling Configuration 20-23 Configuring IGMP Profiles 20-23 Applying IGMP Profiles 20-24 Setting the Maximum Number of IGMP Groups 20-25 Configuring the IGMP Throttling Action 20-25

Displaying IGMP Filtering and Throttling Configuration 20-27

21 Configuring Port-Based Traffic Control 21-1

Configuring Storm Control 21-1

Understanding Storm Control 21-1 Default Storm Control Configuration 21-3 Configuring Storm Control and Threshold Levels 21-3

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Configuring Protected Ports 21-5

Default Protected Port Configuration 21-5 Protected Port Configuration Guidelines 21-6

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Configuring a Protected Port 21-6

Configuring Port Blocking 21-6

Default Port Blocking Configuration 21-6 Blocking Flooded Traffic on an Interface 21-7

Configuring Port Security 21-7

Understanding Port Security 21-8

Secure MAC Addresses 21-8

Security Violations 21-9 Default Port Security Configuration 21-10 Port Security Configuration Guidelines 21-10 Enabling and Configuring Port Security 21-11 Enabling and Configuring Port Security Aging 21-15

Displaying Port-Based Traffic Control Settings 21-16

Contents

CHAPTER

22 Configuring CDP 22-1

Understanding CDP 22-1

Configuring CDP 22-2

Default CDP Configuration 22-2 Configuring the CDP Characteristics 22-2 Disabling and Enabling CDP 22-3 Disabling and Enabling CDP on an Interface 22-4

Monitoring and Maintaining CDP 22-5

23 Configuring SPAN and RSPAN 23-1

Understanding SPAN and RSPAN 23-1

Local SPAN 23-2 Remote SPAN 23-2 SPAN and RSPAN Concepts and Terminology 23-3

SPAN Sessions 23-3

Monitored Traffic 23-4

Source Ports 23-5

Source VLANs 23-6

VLAN Filtering 23-6

Destination Port 23-6

RSPAN VLAN 23-8 SPAN and RSPAN Interaction with Other Features 23-8

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Configuring SPAN and RSPAN 23-9

Default SPAN and RSPAN Configuration 23-9 Configuring Local SPAN 23-10

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SPAN Configuration Guidelines 23-10 Creating a Local SPAN Session 23-10 Creating a Local SPAN Session and Configuring Incoming Traffic 23-13 Specifying VLANs to Filter 23-15

Configuring RSPAN 23-16

RSPAN Configuration Guidelines 23-16 Configuring a VLAN as an RSPAN VLAN 23-17 Creating an RSPAN Source Session 23-18 Creating an RSPAN Destination Session 23-19 Creating an RSPAN Destination Session and Configuring Incoming Traffic 23-20 Specifying VLANs to Filter 23-22

Displaying SPAN and RSPAN Status 23-23

CHAPTER

24 Configuring UDLD 24-1

Understanding UDLD 24-1

Modes of Operation 24-1 Methods to Detect Unidirectional Links 24-2

Configuring UDLD 24-4

Default UDLD Configuration 24-4 Configuration Guidelines 24-4 Enabling UDLD Globally 24-5 Enabling UDLD on an Interface 24-5 Resetting an Interface Disabled by UDLD 24-6

Displaying UDLD Status 24-6

25 Configuring RMON 25-1

Understanding RMON 25-1

Configuring RMON 25-2

Default RMON Configuration 25-3 Configuring RMON Alarms and Events 25-3 Collecting Group History Statistics on an Interface 25-5 Collecting Group Ethernet Statistics on an Interface 25-6

CHAPTER

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Displaying RMON Status 25-6

26 Configuring System Message Logging 26-1

Understanding System Message Logging 26-1

Configuring System Message Logging 26-2

System Log Message Format 26-2

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Default System Message Logging Configuration 26-3 Disabling Message Logging 26-3 Setting the Message Display Destination Device 26-4 Synchronizing Log Messages 26-5 Enabling and Disabling Time Stamps on Log Messages 26-7 Enabling and Disabling Sequence Numbers in Log Messages 26-7 Defining the Message Severity Level 26-8 Limiting Syslog Messages Sent to the History Table and to SNMP 26-9 Configuring UNIX Syslog Servers 26-10

Logging Messages to a UNIX Syslog Daemon 26-11

Configuring the UNIX System Logging Facility 26-11

Displaying the Logging Configuration 26-12

Contents

CHAPTER

27 Configuring SNMP 27-1

Understanding SNMP 27-1

SNMP Versions 27-2 SNMP Manager Functions 27-3 SNMP Agent Functions 27-4 SNMP Community Strings 27-4 Using SNMP to Access MIB Variables 27-4 SNMP Notifications 27-5 SNMP ifIndex MIB Object Values 27-5

Configuring SNMP 27-6

Default SNMP Configuration 27-6 SNMP Configuration Guidelines 27-7 Disabling the SNMP Agent 27-8 Configuring Community Strings 27-8 Configuring SNMP Groups and Users 27-9 Configuring SNMP Notifications 27-11 Setting the Agent Contact and Location Information 27-14 Limiting TFTP Servers Used Through SNMP 27-15 SNMP Examples 27-15

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Displaying SNMP Status 27-16

28 Configuring Network Security with ACLs 28-1

Understanding ACLs 28-1

Port ACLs 28-2 Handling Fragmented and Unfragmented Traffic 28-3

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Configuring IPv4 ACLs 28-4

Creating Standard and Extended IPv4 ACLs 28-5

Access List Numbers 28-6 Creating a Numbered Standard ACL 28-7 Creating a Numbered Extended ACL 28-8 Resequencing ACEs in an ACL 28-12 Creating Named Standard and Extended ACLs 28-12 Using Time Ranges with ACLs 28-14

Including Comments in ACLs 28-15 Applying an IPv4 ACL to a Terminal Line 28-16 Applying an IPv4 ACL to an Interface 28-17 Hardware and Software Treatment of IP ACLs 28-17 IPv4 ACL Configuration Examples 28-18

Numbered ACLs 28-18

Extended ACLs 28-18

Named ACLs 28-19

Time Range Applied to an IP ACL 28-19

Commented IP ACL Entries 28-19

CHAPTER

Creating Named MAC Extended ACLs 28-20

Applying a MAC ACL to a Layer 2 Interface 28-21

Displaying IPv4 ACL Configuration 28-22

29 Configuring QoS 29-1

Understanding QoS 29-1

Basic QoS Model 29-3 Classification 29-5

Classification Based on QoS ACLs 29-7

Classification Based on Class Maps and Policy Maps 29-7 Policing and Marking 29-8

Policing on Physical Ports 29-9 Mapping Tables 29-10 Queueing and Scheduling Overview 29-11

Weighted Tail Drop 29-12

SRR Shaping and Sharing 29-12

Queueing and Scheduling on Ingress Queues 29-13

Queueing and Scheduling on Egress Queues 29-15 Packet Modification 29-18

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Configuring Auto-QoS 29-19

Generated Auto-QoS Configuration 29-19 Effects of Auto-QoS on the Configuration 29-24 Auto-QoS Configuration Guidelines 29-24 Enabling Auto-QoS for VoIP 29-25 Auto-QoS Configuration Example 29-26

Displaying Auto-QoS Information 29-28

Configuring Standard QoS 29-28

Default Standard QoS Configuration 29-29

Default Ingress Queue Configuration 29-29 Default Egress Queue Configuration 29-30 Default Mapping Table Configuration 29-31

Standard QoS Configuration Guidelines 29-31

QoS ACL Guidelines 29-31 Policing Guidelines 29-31

General QoS Guidelines 29-32 Enabling QoS Globally 29-32 Configuring Classification Using Port Trust States 29-32

Configuring the Trust State on Ports within the QoS Domain 29-33

Configuring the CoS Value for an Interface 29-34

Configuring a Trusted Boundary to Ensure Port Security 29-35

Enabling DSCP Transparency Mode 29-36

Configuring the DSCP Trust State on a Port Bordering Another QoS Domain 29-37 Configuring a QoS Policy 29-39

Classifying Traffic by Using ACLs 29-40

Classifying Traffic by Using Class Maps 29-43

Classifying, Policing, and Marking Traffic on Physical Ports by Using Policy Maps 29-45

Classifying, Policing, and Marking Traffic by Using Aggregate Policers 29-48 Configuring DSCP Maps 29-51

Configuring the CoS-to-DSCP Map 29-51

Configuring the IP-Precedence-to-DSCP Map 29-52

Configuring the Policed-DSCP Map 29-53

Configuring the DSCP-to-CoS Map 29-54

Configuring the DSCP-to-DSCP-Mutation Map 29-55 Configuring Ingress Queue Characteristics 29-57

Mapping DSCP or CoS Values to an Ingress Queue and Setting WTD Thresholds 29-57

Allocating Buffer Space Between the Ingress Queues 29-59

Allocating Bandwidth Between the Ingress Queues 29-60

Configuring the Ingress Priority Queue 29-61

Contents

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Contents

Configuring Egress Queue Characteristics 29-62

Configuration Guidelines 29-62 Allocating Buffer Space to and Setting WTD Thresholds for an Egress Queue-Set 29-62 Mapping DSCP or CoS Values to an Egress Queue and to a Threshold ID 29-64 Configuring SRR Shaped Weights on Egress Queues 29-66 Configuring SRR Shared Weights on Egress Queues 29-67 Configuring the Egress Expedite Queue 29-68 Limiting the Bandwidth on an Egress Interface 29-68

Displaying Standard QoS Information 29-69

CHAPTER

30 Configuring EtherChannels 30-1

Understanding EtherChannels 30-1

EtherChannel Overview 30-2 Port-Channel Interfaces 30-3 Port Aggregation Protocol 30-4

PAgP Modes 30-4 PAgP Interaction with Other Features 30-5

Link Aggregation Control Protocol 30-5

LACP Modes 30-5

LACP Interaction with Other Features 30-6 EtherChannel On Mode 30-6 Load Balancing and Forwarding Methods 30-6

Configuring EtherChannels 30-8

Default EtherChannel Configuration 30-9 EtherChannel Configuration Guidelines 30-9 Configuring Layer 2 EtherChannels 30-10 Configuring EtherChannel Load Balancing 30-12 Configuring the PAgP Learn Method and Priority 30-13 Configuring LACP Hot-Standby Ports 30-14

Configuring the LACP System Priority 30-15

Configuring the LACP Port Priority 30-15

CHAPTER

xxii

Displaying EtherChannel, PAgP, and LACP Status 30-16

31 Troubleshooting 31-1

Recovering from a Software Failure 31-2

Recovering from a Lost or Forgotten Password 31-3

Procedure with Password Recovery Enabled 31-4 Procedure with Password Recovery Disabled 31-6

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Recovering from a Command Switch Failure 31-7

Replacing a Failed Command Switch with a Cluster Member 31-8 Replacing a Failed Command Switch with Another Switch 31-9

Recovering from Lost Cluster Member Connectivity 31-11

Preventing Autonegotiation Mismatches 31-11

SFP Module Security and Identification 31-11

Monitoring SFP Module Status 31-12

Using Ping 31-12

Understanding Ping 31-12 Executing Ping 31-13

Using Layer 2 Traceroute 31-13

Understanding Layer 2 Traceroute 31-14 Usage Guidelines 31-14 Displaying the Physical Path 31-15

Contents

APPENDIX

Using IP Traceroute 31-15

Understanding IP Traceroute 31-15 Executing IP Traceroute 31-16

Using TDR 31-17

Understanding TDR 31-17 Running TDR and Displaying the Results 31-17

Using Debug Commands 31-18

Enabling Debugging on a Specific Feature 31-18 Enabling All-System Diagnostics 31-19 Redirecting Debug and Error Message Output 31-19

Using the show platform forward Command 31-19

Using the crashinfo File 31-21

A Supported MIBs A-1

MIB List A-1

Using FTP to Access the MIB Files A-3

B Working with the Cisco IOS File System, Configuration Files, and Software Images B-1

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Working with the Flash File System B-1

Displaying Available File Systems B-2 Setting the Default File System B-3 Displaying Information about Files on a File System B-3 Changing Directories and Displaying the Working Directory B-3 Creating and Removing Directories B-4

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Contents

Copying Files B-4 Deleting Files B-5 Creating, Displaying, and Extracting tar Files B-5

Creating a tar File B-6

Displaying the Contents of a tar File B-6

Extracting a tar File B-7 Displaying the Contents of a File B-8

Working with Configuration Files B-8

Guidelines for Creating and Using Configuration Files B-9 Configuration File Types and Location B-9 Creating a Configuration File By Using a Text Editor B-10 Copying Configuration Files By Using TFTP B-10

Preparing to Download or Upload a Configuration File By Using TFTP B-10

Downloading the Configuration File By Using TFTP B-11

Uploading the Configuration File By Using TFTP B-11 Copying Configuration Files By Using FTP B-12

Preparing to Download or Upload a Configuration File By Using FTP B-13

Downloading a Configuration File By Using FTP B-13

Uploading a Configuration File By Using FTP B-14 Copying Configuration Files By Using RCP B-15

Preparing to Download or Upload a Configuration File By Using RCP B-16

Downloading a Configuration File By Using RCP B-17

Uploading a Configuration File By Using RCP B-18 Clearing Configuration Information B-18

Clearing the Startup Configuration File B-19

Deleting a Stored Configuration File B-19

xxiv

Working with Software Images B-19

Image Location on the Switch B-20 tar File Format of Images on a Server or Cisco.com B-20 Copying Image Files By Using TFTP B-21

Preparing to Download or Upload an Image File By Using TFTP B-21

Downloading an Image File By Using TFTP B-22

Uploading an Image File By Using TFTP B-24 Copying Image Files By Using FTP B-24

Preparing to Download or Upload an Image File By Using FTP B-25

Downloading an Image File By Using FTP B-26

Uploading an Image File By Using FTP B-28

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Copying Image Files By Using RCP B-29

Preparing to Download or Upload an Image File By Using RCP B-29 Downloading an Image File By Using RCP B-31 Uploading an Image File By Using RCP B-32

Contents

APPENDIX

C Recommendations for Upgrading a Catalyst 2950 Switch to a Catalyst 2960 Switch C-1

Configuration Compatibility Issues C-1

Feature Behavior Incompatibilities C-5

D Unsupported Commands in Cisco IOS Release 12.2(25)FX D-1

Access Control Lists D-1

Unsupported Privileged EXEC Commands D-1 Unsupported Global Configuration Commands D-1

Debug Commands D-1

Unsupported Privileged EXEC Commands D-1

IGMP Snooping Commands D-2

Unsupported Global Configuration Commands D-2

Interface Commands D-2

Unsupported Privileged EXEC Commands D-2 Unsupported Global Configuration Commands D-2 Unsupported Interface Configuration Commands D-2

MAC Address Commands D-2

Unsupported Privileged EXEC Commands D-2 Unsupported Global Configuration Commands D-3

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Miscellaneous D-3

Unsupported Privileged EXEC Commands D-3 Unsupported Global Configuration Commands D-3

Network Address Translation (NAT) Commands D-3

Unsupported Privileged EXEC Commands D-3

QoS D-3

Unsupported Global Configuration Commands D-3 Unsupported Interface Configuration Commands D-4

RADIUS D-4

Unsupported Global Configuration Commands D-4

SNMP D-4

Unsupported Global Configuration Commands D-4

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NDEX

Contents

Spanning Tree D-4

Unsupported Global Configuration Command D-4 Unsupported Interface Configuration Command D-4

VLAN D-4

Unsupported Global Configuration Commands D-4 Unsupported vlan-config Command D-5 Unsupported User EXEC Commands D-5

VTP D-5

Unsupported Privileged EXEC Commands D-5

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Audience

Purpose

Preface

This guide is for the networking professional managing the Catalyst 2960 switch, hereafter referred to as the switch. Before using this guide, you should have experience working with the Cisco IOS software and be familiar with the concepts and terminology of Ethernet and local area networking.

This guide provides the information that you need to configure Cisco IOS software features on your switch. The Catalyst 2960 software provides enterprise-class intelligent services such as access control lists (ACLs) and quality of service (QoS) features.

This guide provides procedures for using the commands that have been created or changed for use with the Catalyst 2960 switch. It does not provide detailed information about these commands. For detailed information about these commands, see the Catalyst 2960 Switch Command Reference for this release. For information about the standard Cisco IOS Release 12.2 commands, see the Cisco IOS documentation set available from the Cisco.com home page at Technical Support & Documentation > Cisco IOS Software.

This guide does not provide detailed information on the graphical user interfaces (GUIs) for the embedded device manager or for Cisco Network Assistant (hereafter referred to as Network Assistant) that you can use to manage the switch. However, the concepts in this guide are applicable to the GUI user. For information about the device manager, see the switch online help. For information about Network Assistant, see Getting Started with Cisco Network Assistant, available on Cisco.com

This guide does not describe system messages you might encounter or how to install your switch. For more information, see the Catalyst 2960 Switch System Message Guide for this release and to the Catalyst 2960 Switch Hardware Installation Guide.

For documentation updates, see the release notes for this release.

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Conventions

This publication uses these conventions to convey instructions and information:

Command descriptions use these conventions:

Interactive examples use these conventions:

Notes, cautions, and timesavers use these conventions and symbols:

Preface

• Commands and keywords are in boldface text.

• Arguments for which you supply values are in italic.

• Square brackets ([ ]) mean optional elements.

• Braces ({ }) group required choices, and vertical bars ( | ) separate the alternative elements.

• Braces and vertical bars within square brackets ([{ | }]) mean a required choice within an optional

element.

• Terminal sessions and system displays are in screen font.

• Information you enter is in boldface screen font.

• Nonprinting characters, such as passwords or tabs, are in angle brackets (< >).

Note Means reader take note. Notes contain helpful suggestions or references to materials not contained in

this manual.

Caution Means reader be careful. In this situation, you might do something that could result in equipment

damage or loss of data.

Related Publications

These documents provide complete information about the switch and are available from this Cisco.com site:

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2960/index.htm

Note Before installing, configuring, or upgrading the switch, see these documents:

• For initial configuration information, see the “Using Express Setup” chapter in the getting started

guide or the “Configuring the Switch with the CLI-Based Setup Program” appendix in the hardware installation guide.

• For device manager requirements, see the “System Requirements” section in the release notes (not

orderable but available on Cisco.com).

xxviii

• For Network Assistant requirements, see the Getting Started with Cisco Network Assistant (not

orderable but available on Cisco.com).

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Preface

Obtaining Documentation

• For cluster requirements, see the Release Notes for Cisco Network Assistant (not orderable but

available on Cisco.com).

• For upgrading information, see the “Downloading Software” section in the release notes.

You can order printed copies of documents with a DOC-xxxxxx= number from the Cisco.com sites and from the telephone numbers listed in the “Obtaining Documentation” section on page xxix.

• Release Notes for the Catalyst 2960 Switches (not orderable but available on Cisco.com)

• Catalyst 2960 Switch Software Configuration Guide (order number DOC-7816881=)

• Catalyst 2960 Switch Command Reference (order number DOC-7816882=)

• Catalyst 2960 Switch System Message Guide (order number DOC-7816883=)

• Device manager online help (available on the switch)

• Catalyst 2960 Switch Hardware Installation Guide (not orderable but available on Cisco.com)

• Catalyst 2960 Switch Getting Started Guide (order number DOC-7816879=)

• Regulatory Compliance and Safety Information for the Catalyst 2960 Switch (order number

DOC-7816880=)

• Getting Started with Cisco Network Assistant (not orderable but available on Cisco.com)

• Release Notes for Cisco Network Assistant (not orderable but available on Cisco.com)

• Cisco Small Form-Factor Pluggable Modules Installation Notes (order number DOC-7815160=)

• Cisco CWDM GBIC and CWDM SFP Installation Note (not orderable but available on Cisco.com)

• Cisco RPS 300 Redundant Power System Hardware Installation Guide (order number

DOC-7810372=)

• Cisco RPS 675 Redundant Power System Hardware Installation Guide (order number

DOC-7815201=)

Obtaining Documentation

Cisco documentation and additional literature are available on Cisco.com. Cisco also provides several ways to obtain technical assistance and other technical resources. These sections explain how to obtain technical information from Cisco Systems.

Cisco.com

You can access the most current Cisco documentation at this URL:

http://www.cisco.com/techsupport

You can access the Cisco website at this URL:

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http://www.cisco.com

You can access international Cisco websites at this URL:

http://www.cisco.com/public/countries_languages.shtml

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xxix

Documentation Feedback

Product Documentation DVD

Cisco documentation and additional literature are available in the Product Documentation DVD package, which may have shipped with your product. The Product Documentation DVD is updated regularly and may be more current than printed documentation.

The Product Documentation DVD is a comprehensive library of technical product documentation on portable media. The DVD enables you to access multiple versions of hardware and software installation, configuration, and command guides for Cisco products and to view technical documentation in HTML. With the DVD, you have access to the same documentation that is found on the Cisco website without being connected to the Internet. Certain products also have .pdf versions of the documentation available.

The Product Documentation DVD is available as a single unit or as a subscription. Registered Cisco.com users (Cisco direct customers) can order a Product Documentation DVD (product number DOC-DOCDVD=) from Cisco Marketplace at this URL:

http://www.cisco.com/go/marketplace/

Ordering Documentation

Preface

Beginning June 30, 2005, registered Cisco.com users may order Cisco documentation at the Product Documentation Store in the Cisco Marketplace at this URL:

http://www.cisco.com/go/marketplace/

Nonregistered Cisco.com users can order technical documentation from 8:00 a.m. to 5:00 p.m. (0800 to 1700) PDT by calling 1 866 463-3487 in the United States and Canada, or elsewhere by calling 011 408 519-5055. You can also order documentation by e-mail at

tech-doc-store-mkpl@external.cisco.com or by fax at 1 408 519-5001 in the United States and Canada,

or elsewhere at 011 408 519-5001.

Documentation Feedback

You can rate and provide feedback about Cisco technical documents by completing the online feedback form that appears with the technical documents on Cisco.com.

You can send comments about Cisco documentation to bug-doc@cisco.com.

You can submit comments by using the response card (if present) behind the front cover of your document or by writing to the following address:

Cisco Systems Attn: Customer Document Ordering 170 West Tasman Drive San Jose, CA 95134-9883

xxx

We appreciate your comments.

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Preface

Cisco Product Security Overview

Cisco provides a free online Security Vulnerability Policy portal at this URL:

http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html

From this site, you can perform these tasks:

• Report security vulnerabilities in Cisco products.

• Obtain assistance with security incidents that involve Cisco products.

• Register to receive security information from Cisco.

A current list of security advisories and notices for Cisco products is available at this URL:

http://www.cisco.com/go/psirt

If you prefer to see advisories and notices as they are updated in real time, you can access a Product Security Incident Response Team Really Simple Syndication (PSIRT RSS) feed from this URL:

http://www.cisco.com/en/US/products/products_psirt_rss_feed.html

Cisco Product Security Overview

Reporting Security Problems in Cisco Products

Cisco is committed to delivering secure products. We test our products internally before we release them, and we strive to correct all vulnerabilities quickly. If you think that you might have identified a vulnerability in a Cisco product, contact PSIRT:

• Emergencies—security-alert@cisco.com

An emergency is either a condition in which a system is under active attack or a condition for which a severe and urgent security vulnerability should be reported. All other conditions are considered nonemergencies.

• Nonemergencies — psirt@cisco.com

In an emergency, you can also reach PSIRT by telephone:

• 1 877 228-7302

• 1 408 525-6532

Tip We encourage you to use Pretty Good Privacy (PGP) or a compatible product to encrypt any sensitive

information that you send to Cisco. PSIRT can work from encrypted information that is compatible with PGP versions 2.x through 8.x.

Never use a revoked or an expired encryption key. The correct public key to use in your correspondence with PSIRT is the one linked in the Contact Summary section of the Security Vulnerability Policy page at this URL:

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http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html

The link on this page has the current PGP key ID in use.

Catalyst 2960 Switch Software Configuration Guide

xxxi

Obtaining Technical Assistance

Cisco Technical Support provides 24-hour-a-day award-winning technical assistance. The Cisco Technical Support & Documentation website on Cisco.com features extensive online support resources. In addition, if you have a valid Cisco service contract, Cisco Technical Assistance Center (TAC) engineers provide telephone support. If you do not have a valid Cisco service contract, contact your reseller.

Cisco Technical Support & Documentation Website

The Cisco Technical Support & Documentation website provides online documents and tools for troubleshooting and resolving technical issues with Cisco products and technologies. The website is available 24 hours a day, at this URL:

http://www.cisco.com/techsupport

Access to all tools on the Cisco Technical Support & Documentation website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register at this URL:

Preface

http://tools.cisco.com/RPF/register/register.do

Note Use the Cisco Product Identification (CPI) tool to locate your product serial number before submitting

a web or phone request for service. You can access the CPI tool from the Cisco Technical Support & Documentation website by clicking the Tools & Resources link under Documentation & Tools. Choose

Cisco Product Identification Tool from the Alphabetical Index drop-down list, or click the Cisco Product Identification Tool link under Alerts & RMAs. The CPI tool offers three search options: by

product ID or model name; by tree view; or for certain products, by copying and pasting show command output. Search results show an illustration of your product with the serial number label location highlighted. Locate the serial number label on your product and record the information before placing a service call.

Submitting a Service Request

Using the online TAC Service Request Tool is the fastest way to open S3 and S4 service requests. (S3 and S4 service requests are those in which your network is minimally impaired or for which you require product information.) After you describe your situation, the TAC Service Request Tool provides recommended solutions. If your issue is not resolved using the recommended resources, your service request is assigned to a Cisco engineer. The TAC Service Request Tool is located at this URL:

http://www.cisco.com/techsupport/servicerequest

For S1 or S2 service requests or if you do not have Internet access, contact the Cisco TAC by telephone. (S1 or S2 service requests are those in which your production network is down or severely degraded.) Cisco engineers are assigned immediately to S1 and S2 service requests to help keep your business operations running smoothly.

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Preface

To open a service request by telephone, use one of the following numbers:

Asia-Pacific: +61 2 8446 7411 (Australia: 1 800 805 227) EMEA: +32 2 704 55 55 USA: 1 800 553-2447

For a complete list of Cisco TAC contacts, go to this URL:

http://www.cisco.com/techsupport/contacts

Definitions of Service Request Severity

To ensure that all service requests are reported in a standard format, Cisco has established severity definitions.

Severity 1 (S1)—Your network is “down,” or there is a critical impact to your business operations. You and Cisco will commit all necessary resources around the clock to resolve the situation.

Severity 2 (S2)—Operation of an existing network is severely degraded, or significant aspects of your business operation are negatively affected by inadequate performance of Cisco products. You and Cisco will commit full-time resources during normal business hours to resolve the situation.

Obtaining Additional Publications and Information

Severity 3 (S3)—Operational performance of your network is impaired, but most business operations remain functional. You and Cisco will commit resources during normal business hours to restore service to satisfactory levels.

Severity 4 (S4)—You require information or assistance with Cisco product capabilities, installation, or configuration. There is little or no effect on your business operations.

Obtaining Additional Publications and Information

Information about Cisco products, technologies, and network solutions is available from various online and printed sources.

• Cisco Marketplace provides a variety of Cisco books, reference guides, documentation, and logo

merchandise. Visit Cisco Marketplace, the company store, at this URL:

http://www.cisco.com/go/marketplace/

• Cisco Press publishes a wide range of general networking, training and certification titles. Both new

and experienced users will benefit from these publications. For current Cisco Press titles and other information, go to Cisco Press at this URL:

http://www.ciscopress.com

• Packet magazine is the Cisco Systems technical user magazine for maximizing Internet and

networking investments. Each quarter, Packet delivers coverage of the latest industry trends, technology breakthroughs, and Cisco products and solutions, as well as network deployment and troubleshooting tips, configuration examples, customer case studies, certification and training information, and links to scores of in-depth online resources. You can access Packet magazine at this URL:

78-16881-01

http://www.cisco.com/packet

Catalyst 2960 Switch Software Configuration Guide

xxxiii

Obtaining Additional Publications and Information

• iQ Magazine is the quarterly publication from Cisco Systems designed to help growing companies

learn how they can use technology to increase revenue, streamline their business, and expand services. The publication identifies the challenges facing these companies and the technologies to help solve them, using real-world case studies and business strategies to help readers make sound technology investment decisions. You can access iQ Magazine at this URL:

http://www.cisco.com/go/iqmagazine

or view the digital edition at this URL:

http://ciscoiq.texterity.com/ciscoiq/sample/

• Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering

professionals involved in designing, developing, and operating public and private internets and intranets. You can access the Internet Protocol Journal at this URL:

http://www.cisco.com/ipj

• Networking products offered by Cisco Systems, as well as customer support services, can be

obtained at this URL:

http://www.cisco.com/en/US/products/index.html

• Networking Professionals Connection is an interactive website for networking professionals to share

questions, suggestions, and information about networking products and technologies with Cisco experts and other networking professionals. Join a discussion at this URL:

Preface

http://www.cisco.com/discuss/networking

• World-class networking training is available from Cisco. You can view current offerings at

this URL:

http://www.cisco.com/en/US/learning/index.html

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Features

CHAPTER

Overview

This chapter provides these topics about the Catalyst 2960 switch software:

• Features, page 1-1

• Default Settings After Initial Switch Configuration, page 1-8

• Network Configuration Examples, page 1-11

• Where to Go Next, page 1-16

In this document, IP refers to IP Version 4 (IPv4).

Some features described in this chapter are available only on the cryptographic (supports encryption) version of the software. You must obtain authorization to use this feature and to download the cryptographic version of the software from Cisco.com. For more information, see the release notes for this release.

The switch has these features:

• Ease-of-Use and Ease-of-Deployment Features, page 1-2

• Performance Features, page 1-3

• Management Options, page 1-3

• Manageability Features, page 1-4 (includes a feature requiring the cryptographic version of the

software)

• Availability Features, page 1-5

• VLAN Features, page 1-6

• Security Features, page 1-6 (includes a feature requiring the cryptographic version of the software)

• QoS and CoS Features, page 1-7

• Monitoring Features, page 1-8

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1-1

Features

Ease-of-Use and Ease-of-Deployment Features

• Express Setup for quickly configuring a switch for the first time with basic IP information, contact

information, switch and Telnet passwords, and Simple Network Management Protocol (SNMP) information through a browser-based program. For more information about Express Setup, see the getting started guide.

• User-defined and Cisco-default Smartports macros for creating custom switch configurations for

simplified deployment across the network.

• An embedded device manager GUI for configuring and monitoring a single switch through a web

browser. For information about launching the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

• Cisco Network Assistant (hereafter referred to as Network Assistant) for

–

Managing communities, which are device groups like clusters, except that they can contain routers and access points and can be made more secure.

–

Simplifying and minimizing switch and switch cluster management from anywhere in your intranet.

–

Accomplishing multiple configuration tasks from a single graphical interface without needing to remember command-line interface (CLI) commands to accomplish specific tasks.

Chapter 1 Overview

–

Interactive guide mode that guides you in configuring complex features such as VLANs, ACLs, and quality of service (QoS).

–

Configuration wizards that prompt you to provide only the minimum required information to configure complex features such as QoS priorities for video traffic, priority levels for data applications, and security.

–

Downloading an image to a switch.

–

Applying actions to multiple ports and multiple switches at the same time, such as VLAN and QoS settings, inventory and statistic reports, link- and switch-level monitoring and troubleshooting, and multiple switch software upgrades.

–

Viewing a topology of interconnected devices to identify existing switch clusters and eligible switches that can join a cluster and to identify link information between switches.

–

Monitoring real-time status of a switch or multiple switches from the LEDs on the front-panel images. The system, redundant power system (RPS), and port LED colors on the images are similar to those used on the physical LEDs.

• Switch clustering technology for

–

Unified configuration, monitoring, authentication, and software upgrade of multiple, cluster-capable switches, regardless of their geographic proximity and interconnection media, including Ethernet, Fast Ethernet, Fast EtherChannel, small form-factor pluggable (SFP) modules, Gigabit Ethernet, and Gigabit EtherChannel connections. For a list of cluster-capable switches, see the release notes.

–

Automatic discovery of candidate switches and creation of clusters of up to 16 switches that can be managed through a single IP address.

1-2

–

Extended discovery of cluster candidates that are not directly connected to the command switch.

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Chapter 1 Overview

Performance Features

• Autosensing of port speed and autonegotiation of duplex mode on all switch ports for optimizing

bandwidth

• Automatic-medium-dependent interface crossover (auto-MDIX) capability on 10/100 and

10/100/1000 Mbps interfaces and on 10/100/1000 BASE-TX SFP module interface that enables the interface to automatically detect the required cable connection type (straight-through or crossover) and to configure the connection appropriately

• Support for up to 9000 bytes for frames that are bridged in hardware and up to 2000 bytes for frames

that are bridged by software

• IEEE 802.3x flow control on all ports (the switch does not send pause frames)

• EtherChannel for enhanced fault tolerance and for providing up to 8 Gbps (Gigabit EtherChannel)

or 800 Mbps (Fast EtherChannel) full-duplex bandwidth among switches, routers, and servers

• Port Aggregation Protocol (PAgP) and Link Aggregation Control Protocol (LACP) for automatic

creation of EtherChannel links

• Forwarding of Layer 2 packets at Gigabit line rate

Features

• Per-port storm control for preventing broadcast, multicast, and unicast storms

• Port blocking on forwarding unknown Layer 2 unknown unicast, multicast, and bridged broadcast

traffic

• Internet Group Management Protocol (IGMP) snooping for IGMP Versions 1, 2, and 3 for

efficiently forwarding multimedia and multicast traffic

• IGMP report suppression for sending only one IGMP report per multicast router query to the

multicast devices (supported only for IGMPv1 or IGMPv2 queries)

• IGMP snooping querier support to configure switch to generate periodic IGMP General Query

messages

• Multicast VLAN registration (MVR) to continuously send multicast streams in a multicast VLAN

while isolating the streams from subscriber VLANs for bandwidth and security reasons

• IGMP filtering for controlling the set of multicast groups to which hosts on a switch port can belong

• IGMP throttling for configuring the action when the maximum number of entries is in the IGMP

forwarding table

• IGMP configurable leave timer to configure the leave latency for the network.

• Switch Database Management (SDM) templates for allocating system resources to maximize

support for user-selected features

Management Options

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• An embedded device manager—The device manager is a GUI that is integrated in the software

image. You use it to configure and to monitor a single switch. For information about launching the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

• Network Assistant—Network Assistant is a network management application that can be

downloaded from Cisco.com. You use it to manage a single switch, a cluster of switches, or a community of devices. For more information about Network Assistant, see Getting Started with Cisco Network Assistant, available on Cisco.com.

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Features

• CLI—The Cisco IOS software supports desktop- and multilayer-switching features. You can access

the CLI either by connecting your management station directly to the switch console port or by using Telnet from a remote management station. For more information about the CLI, see Chapter 2,

“Using the Command-Line Interface.”

• SNMP—SNMP management applications such as CiscoWorks2000 LAN Management Suite (LMS)

and HP OpenView. You can manage from an SNMP-compatible management station that is running platforms such as HP OpenView or SunNet Manager. The switch supports a comprehensive set of MIB extensions and four remote monitoring (RMON) groups. For more information about using SNMP, see Chapter 27, “Configuring SNMP.”

• IE2100—Cisco Intelligence Engine 2100 Series Configuration Registrar is a network management

device that works with embedded Cisco Networking Services (CNS) agents in the switch software. You can automate initial configurations and configuration updates by generating switch-specific configuration changes, sending them to the switch, executing the configuration change, and logging the results.

For more information about IE2100, see Chapter 4, “Understanding CNS Embedded Agents.”

Manageability Features

Chapter 1 Overview

• Cisco IE2100 Series CNS embedded agents for automating switch management, configuration

storage, and delivery

• DHCP for automating configuration of switch information (such as IP address, default gateway,

hostname, and Domain Name System [DNS] and TFTP server names)

• DHCP relay for forwarding User Datagram Protocol (UDP) broadcasts, including IP address

requests, from DHCP clients

• DHCP server for automatic assignment of IP addresses and other DHCP options to IP hosts

• Directed unicast requests to a DNS server for identifying a switch through its IP address and its

corresponding hostname and to a TFTP server for administering software upgrades from a TFTP server

• Address Resolution Protocol (ARP) for identifying a switch through its IP address and its

corresponding MAC address

• Unicast MAC address filtering to drop packets with specific source or destination MAC addresses

• Cisco Discovery Protocol (CDP) Versions 1 and 2 for network topology discovery and mapping

between the switch and other Cisco devices on the network

• Network Time Protocol (NTP) for providing a consistent time stamp to all switches from an external

source

• Cisco IOS File System (IFS) for providing a single interface to all file systems that the switch uses

• Unique device identifier to provide product identification information through a show inventory

user EXEC command display

1-4

• In-band management access through the device manager over a Netscape Navigator or Microsoft

Internet Explorer browser session

• In-band management access for up to 16 simultaneous Telnet connections for multiple CLI-based

sessions over the network

• In-band management access for up to five simultaneous, encrypted Secure Shell (SSH) connections

for multiple CLI-based sessions over the network (requires the cryptographic version of the software)

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Chapter 1 Overview

• In-band management access through SNMP Versions 1, 2c, and 3 get and set requests

• Out-of-band management access through the switch console port to a directly attached terminal or

to a remote terminal through a serial connection or a modem

Note For additional descriptions of the management interfaces, see the “Network Configuration Examples”

section on page 1-11.

Availability Features

• UniDirectional Link Detection (UDLD) and aggressive UDLD for detecting and disabling

unidirectional links on fiber-optic interfaces caused by incorrect fiber-optic wiring or port faults

• IEEE 802.1D Spanning Tree Protocol (STP) for redundant backbone connections and loop-free

networks. STP has these features:

–

Up to 128 spanning-tree instances supported

–

Per-VLAN spanning-tree plus (PVST+) for balancing load across VLANs

Features

–

Rapid PVST+ for balancing load across VLANs and providing rapid convergence of spanning-tree instances

–

UplinkFast and BackboneFast for fast convergence after a spanning-tree topology change and for achieving load balancing between redundant uplinks, including Gigabit uplinks

• IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) for grouping VLANs into a spanning-tree

instance and for providing multiple forwarding paths for data traffic and load balancing and rapid per-VLAN Spanning-Tree plus (rapid-PVST+) based on the IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) for rapid convergence of the spanning tree by immediately transitioning root and designated ports to the forwarding state

• Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP mode:

–

Port Fast for eliminating the forwarding delay by enabling a port to immediately transition from the blocking state to the forwarding state

–

BPDU guard for shutting down Port Fast-enabled ports that receive bridge protocol data units (BPDUs)

–

BPDU filtering for preventing a Port Fast-enabled port from sending or receiving BPDUs

–

Root guard for preventing switches outside the network core from becoming the spanning-tree root

–

Loop guard for preventing alternate or root ports from becoming designated ports because of a failure that leads to a unidirectional link

• Flex Link Layer 2 interfaces to back up one another as an alternative to STP for basic link

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• RPS support through the Cisco RPS 300 and Cisco RPS 675 for enhancing power reliability

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Features

VLAN Features

Chapter 1 Overview

• Support for up to 255 VLANs for assigning users to VLANs associated with appropriate network

resources, traffic patterns, and bandwidth

• Support for VLAN IDs in the 1 to 4094 range as allowed by the IEEE 802.1Q standard

• VLAN Query Protocol (VQP) for dynamic VLAN membership

• IEEE 802.1Q trunking encapsulation on all ports for network moves, adds, and changes;

management and control of broadcast and multicast traffic; and network security by establishing VLAN groups for high-security users and network resources

• Dynamic Trunking Protocol (DTP) for negotiating trunking on a link between two devices and for

negotiating the type of trunking encapsulation (IEEE 802.1Q) to be used

• VLAN Trunking Protocol (VTP) and VTP pruning for reducing network traffic by restricting

flooded traffic to links destined for stations receiving the traffic

• Voice VLAN for creating subnets for voice traffic from Cisco IP Phones

• VLAN1 minimization for reducing the risk of spanning-tree loops or storms by allowing VLAN 1

to be disabled on any individual VLAN trunk link. With this feature enabled, no user traffic is sent or received on the trunk. The switch CPU continues to send and receive control protocol frames.

Security Features

• Password-protected access (read-only and read-write access) to management interfaces (device

• Multilevel security for a choice of security level, notification, and resulting actions

• Static MAC addressing for ensuring security

• Protected port option for restricting the forwarding of traffic to designated ports on the same switch

• Port security option for limiting and identifying MAC addresses of the stations allowed to access

• Port security aging to set the aging time for secure addresses on a port

• BPDU guard for shutting down a Port Fast-configured port when an invalid configuration occurs

• Standard and extended IP access control lists (ACLs) for defining inbound security policies on Layer

• Extended MAC access control lists for defining security policies in the inbound direction on Layer 2

• Source and destination MAC-based ACLs for filtering non-IP traffic

• DHCP snooping to filter untrusted DHCP messages between untrusted hosts and DHCP servers

• IEEE 802.1x port-based authentication to prevent unauthorized devices (clients) from gaining

manager, Network Assistant, CLI) for protection against unauthorized configuration changes

the port

2 interfaces (port ACLs)

interfaces

access to the network. These features are supported:

–

VLAN assignment for restricting IEEE 802.1x-authenticated users to a specified VLAN

1-6

–

Port security for controlling access to IEEE 802.1x ports

–

Voice VLAN to permit a Cisco IP Phone to access the voice VLAN regardless of the authorized or unauthorized state of the port

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Chapter 1 Overview

–

Guest VLAN to provide limited services to non-IEEE 802.1x-compliant users

–

IEEE 802.1x accounting to track network usage

• TACACS+, a proprietary feature for managing network security through a TACACS server

• RADIUS for verifying the identity of, granting access to, and tracking the actions of remote users

through authentication, authorization, and accounting (AAA) services

• SecureSocket Layer (SSL) Version 3.0 support for the HTTP1.1 server authentication, encryption,

and message integrity, and HTTP client authentication to allow secure HTTP communications (requires the cryptographic version of the software)

QoS and CoS Features

• Automatic QoS (auto-QoS) to simplify the deployment of existing QoS features by classifying

traffic and configuring egress queues

• Classification

–

IP type-of-service/Differentiated Services Code Point (IP ToS/DSCP) and IEEE 802.1p CoS marking priorities on a per-port basis for protecting the performance of mission-critical applications

–

IP ToS/DSCP and IEEE 802.1p CoS marking based on flow-based packet classification (classification based on information in the MAC, IP, and TCP/UDP headers) for high-performance quality of service at the network edge, allowing for differentiated service levels for different types of network traffic and for prioritizing mission-critical traffic in the network

Features

–

Trusted port states (CoS, DSCP, and IP precedence) within a QoS domain and with a port bordering another QoS domain

–

Trusted boundary for detecting the presence of a Cisco IP Phone, trusting the CoS value received, and ensuring port security

• Policing

–

Traffic-policing policies on the switch port for managing how much of the port bandwidth should be allocated to a specific traffic flow

–

Aggregate policing for policing traffic flows in aggregate to restrict specific applications or traffic flows to metered, predefined rates

• Out-of-Profile

–

Out-of-profile markdown for packets that exceed bandwidth utilization limits

• Ingress queueing and scheduling

–

Two configurable ingress queues for user traffic (one queue can be the priority queue)

–

Weighted tail drop (WTD) as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

–

Shaped round robin (SRR) as the scheduling service for specifying the rate at which packets are sent to the internal ring (sharing is the only supported mode on ingress queues)

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Default Settings After Initial Switch Configuration

• Egress queues and scheduling

–

Four egress queues per port

–

WTD as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

–

SRR as the scheduling service for specifying the rate at which packets are dequeued to the egress interface (shaping or sharing is supported on egress queues). Shaped egress queues are guaranteed but limited to using a share of port bandwidth. Shared egress queues are also guaranteed a configured share of bandwidth, but can use more than the guarantee if other queues become empty and do not use their share of the bandwidth.

Monitoring Features

• Switch LEDs that provide port- and switch-level status

• MAC address notification traps and RADIUS accounting for tracking users on a network by storing

the MAC addresses that the switch has learned or removed

• Switched Port Analyzer (SPAN) and Remote SPAN (RSPAN) for traffic monitoring on any port or

VLAN

Chapter 1 Overview

• SPAN and RSPAN support of Intrusion Detection Systems (IDS) to monitor, repel, and report

network security violations

• Four groups (history, statistics, alarms, and events) of embedded RMON agents for network

monitoring and traffic analysis

• Syslog facility for logging system messages about authentication or authorization errors, resource

issues, and time-out events

• Layer 2 traceroute to identify the physical path that a packet takes from a source device to a

destination device

• Time Domain Reflector (TDR) to diagnose and resolve cabling problems on 10/100 and

10/100/1000 copper Ethernet ports

• SFP module diagnostic management interface to monitor physical or operational status of an SFP

module

Default Settings After Initial Switch Configuration

The switch is designed for plug-and-play operation, requiring only that you assign basic IP information to the switch and connect it to the other devices in your network. If you have specific network needs, you can change the interface-specific and system-wide settings.

Note For information about assigning an IP address by using the browser-based Express Setup program, see

the getting started guide. For information about assigning an IP address by using the CLI-based setup program, see the hardware installation guide.

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Chapter 1 Overview

Default Settings After Initial Switch Configuration

If you do not configure the switch at all, the switch operates with these default settings:

• Default switch IP address, subnet mask, and default gateway is 0.0.0.0. For more information, see

Chapter 3, “Assigning the Switch IP Address and Default Gateway,” and Chapter 19, “Configuring DHCP Features.”

• Default domain name is not configured. For more information, see Chapter 3, “Assigning the Switch

IP Address and Default Gateway.”

• DHCP client is enabled, the DHCP server is enabled (only if the device acting as a DHCP server is

configured and is enabled), and the DHCP relay agent is enabled (only if the device is acting as a DHCP relay agent is configured and is enabled). For more information, see Chapter 3, “Assigning

the Switch IP Address and Default Gateway,” and Chapter 19, “Configuring DHCP Features.”

• Switch cluster is disabled. For more information about switch clusters, see Chapter 5, “Clustering

Switches,” and the Getting Started with Cisco Network Assistant, available on Cisco.com.

• No passwords are defined. For more information, see Chapter 6, “Administering the Switch.”

• System name and prompt is Switch. For more information, see Chapter 6, “Administering the

Switch.”

• NTP is enabled. For more information, see Chapter 6, “Administering the Switch.”

• DNS is enabled. For more information, see Chapter 6, “Administering the Switch.”

• TACACS+ is disabled. For more information, see Chapter 8, “Configuring Switch-Based

Authentication.”

• RADIUS is disabled. For more information, see Chapter 8, “Configuring Switch-Based

Authentication.”

• The standard HTTP server and Secure Socket Layer (SSL) HTTPS server are both enabled. For more

information, see Chapter 8, “Configuring Switch-Based Authentication.”

• IEEE 802.1x is disabled. For more information, see Chapter 9, “Configuring IEEE 802.1x

Port-Based Authentication.”

• Port parameters

–

Interface speed and duplex mode is autonegotiate. For more information, see Chapter 10,

“Configuring Interface Characteristics.”

–

Auto-MDIX is enabled. For more information, see Chapter 10, “Configuring Interface

Characteristics.”

–

Flow control is off. For more information, see Chapter 10, “Configuring Interface

Characteristics.”

• No Smartports macros are defined. For more information, see Chapter 11, “Configuring Smartports

Macros.”

• VLANs

–

Default VLAN is VLAN 1. For more information, see Chapter 12, “Configuring VLANs.”

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–

VLAN trunking setting is dynamic auto (DTP). For more information, see Chapter 12,

“Configuring VLANs.”

–

Trunk encapsulation is negotiate. For more information, see Chapter 12, “Configuring

VLANs.”

–

VTP mode is server. For more information, see Chapter 13, “Configuring VTP.”

–

VTP version is Version 1. For more information, see Chapter 13, “Configuring VTP.”

–

Voice VLAN is disabled. For more information, see Chapter 14, “Configuring Voice VLAN.”

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Default Settings After Initial Switch Configuration

• For STP, PVST+ is enabled on VLAN 1. For more information, see Chapter 15, “Configuring STP.”

• MSTP is disabled. For more information, see Chapter 16, “Configuring MSTP.”

• Optional spanning-tree features are disabled. For more information, see Chapter 17, “Configuring

Optional Spanning-Tree Features.”

• Flex Links are not configured. For more information, see Chapter 18, “Configuring Flex Links.”

• DHCP snooping is disabled. The DHCP snooping information option is enabled. For more

information, see Chapter 19, “Configuring DHCP Features.”

• IGMP snooping is enabled. No IGMP filters are applied. For more information, see Chapter 20,

“Configuring IGMP Snooping and MVR.”

• IGMP throttling setting is deny. For more information, see Chapter 20, “Configuring IGMP

Snooping and MVR.”

• The IGMP snooping querier feature is disabled. For more information, see Chapter 20, “Configuring

IGMP Snooping and MVR.”

• MVR is disabled. For more information, see Chapter 20, “Configuring IGMP Snooping and MVR.”

• Port-based traffic

–

Broadcast, multicast, and unicast storm control is disabled. For more information, see

Chapter 21, “Configuring Port-Based Traffic Control.”

Chapter 1 Overview

–

No protected ports are defined. For more information, see Chapter 21, “Configuring Port-Based

Traffic Control.”

–

Unicast and multicast traffic flooding is not blocked. For more information, see Chapter 21,

“Configuring Port-Based Traffic Control.”

–

No secure ports are configured. For more information, see Chapter 21, “Configuring Port-Based

Traffic Control.”

• CDP is enabled. For more information, see Chapter 22, “Configuring CDP.”

• UDLD is disabled. For more information, see Chapter 24, “Configuring UDLD.”

• SPAN and RSPAN are disabled. For more information, see Chapter 23, “Configuring SPAN and

RSPAN.”

• RMON is disabled. For more information, see Chapter 25, “Configuring RMON.”

• Syslog messages are enabled and appear on the console. For more information, see Chapter 26,

“Configuring System Message Logging.”

• SNMP is enabled (Version 1). For more information, see Chapter 27, “Configuring SNMP.”

• No ACLs are configured. For more information, see Chapter 28, “Configuring Network Security

with ACLs.”

• QoS is disabled. For more information, see Chapter 29, “Configuring QoS.”

• No EtherChannels are configured. For more information, see Chapter 30, “Configuring

EtherChannels.”

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Chapter 1 Overview

Network Configuration Examples

This section provides network configuration concepts and includes examples of using the switch to create dedicated network segments and interconnecting the segments through Fast Ethernet and Gigabit Ethernet connections.

• “Design Concepts for Using the Switch” section on page 1-11

• “Small to Medium-Sized Network Using Catalyst 2960 Switches” section on page 1-14

• “Long-Distance, High-Bandwidth Transport Configuration” section on page 1-15

Design Concepts for Using the Switch

As your network users compete for network bandwidth, it takes longer to send and receive data. When you configure your network, consider the bandwidth required by your network users and the relative priority of the network applications they use.

Table 1-1 describes what can cause network performance to degrade and how you can configure your

network to increase the bandwidth available to your network users.

Network Configuration Examples

Table 1-1 Increasing Network Performance

Network Demands Suggested Design Methods

Too many users on a single network segment and a growing number of users accessing the Internet

• Increased power of new PCs,

workstations, and servers

• High bandwidth demand from

networked applications (such as e-mail with large attached files) and from bandwidth-intensive applications (such as multimedia)

• Create smaller network segments so that fewer users share the bandwidth, and use

VLANs and IP subnets to place the network resources in the same logical network as the users who access those resources most.

• Use full-duplex operation between the switch and its connected workstations.

• Connect global resources—such as servers and routers to which the network users

require equal access—directly to the high-speed switch ports so that they have their own high-speed segment.

• Use the EtherChannel feature between the switch and its connected servers and

routers.

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Network Configuration Examples

Bandwidth alone is not the only consideration when designing your network. As your network traffic profiles evolve, consider providing network services that can support applications for voice and data integration, multimedia integration, application prioritization, and security. Table 1 - 2 describes some network demands and how you can meet them.

Table 1-2 Providing Network Services

Network Demands Suggested Design Methods

Efficient bandwidth usage for multimedia applications and guaranteed bandwidth for critical applications

High demand on network redundancy and availability to provide always on mission-critical applications

An evolving demand for IP telephony

• Use IGMP snooping to efficiently forward multimedia and multicast traffic.

• Use other QoS mechanisms such as packet classification, marking, scheduling,

and congestion avoidance to classify traffic with the appropriate priority level, thereby providing maximum flexibility and support for mission-critical, unicast, and multicast and multimedia applications.

• Use MVR to continuously send multicast streams in a multicast VLAN but to

isolate the streams from subscriber VLANs for bandwidth and security reasons.

• Use Hot Standby Router Protocol (HSRP) for cluster command switch

redundancy.

• Use VLAN trunks and BackboneFast for traffic-load balancing on the uplink ports

so that the uplink port with a lower relative port cost is selected to carry the VLAN traffic.

• Use QoS to prioritize applications such as IP telephony during congestion and to

help control both delay and jitter within the network.

• Use switches that support at least two queues per port to prioritize voice and data

traffic as either high- or low-priority, based on IEEE 802.1p/Q. The switch supports at least four queues per port.

Chapter 1 Overview

A growing demand for using existing infrastructure to transport data and voice from a home or office to the Internet or an intranet at higher speeds

• You can use the switches to create the following:

• Cost-effective Gigabit-to-the-desktop for high-performance workgroups (Figure 1-1)—For

high-speed access to network resources, you can use Catalyst 2960 switches in the access layer to provide Gigabit Ethernet to the desktop. To prevent congestion, use QoS DSCP marking priorities on these switches. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to a Gigabit multilayer switch with routing capability, such as a Catalyst 3750 switch, or to a router.

The first illustration is of an isolated high-performance workgroup, where the Catalyst 2960 switches are connected to Catalyst 3750 switches in the distribution layer. The second illustration is of a high-performance workgroup in a branch office, where the Catalyst 2960 switches are connected to a router in the distribution layer.

Each switch in this configuration provides users with a dedicated 1-Gbps connection to network resources. Using SFP modules also provides flexibility in media and distance options through fiber-optic connections.

• Use voice VLAN IDs (VVIDs) to provide separate VLANs for voice traffic.

Use the Catalyst Long-Reach Ethernet (LRE) switches to provide up to 15 Mb of IP connectivity over existing infrastructure, such as existing telephone lines.

Note LRE is the technology used in the Catalyst 2900 LRE XL and Catalyst 2950

LRE switches. See the documentation sets specific to these switches for LRE information.

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Chapter 1 Overview

Network Configuration Examples

Figure 1-1 High-Performance Workgroup (Gigabit-to-the-Desktop)

Catalyst 3750 switches

Access-layer Catalyst switches

89373

WAN

Cisco 2600 router

Access-layer Catalyst switches

89374

Server aggregation (Figure 1-2)—You can use the switches to interconnect groups of servers,

•

centralizing physical security and administration of your network. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to multilayer switches with routing capability. The Gigabit interconnections minimize latency in the data flow.

QoS and policing on the switches provide preferential treatment for certain data streams, if required. They segment traffic streams into different paths for processing. Security features on the switch ensure rapid handling of packets.

Fault tolerance from the server racks to the core is achieved through dual homing of servers connected to the switches, which have redundant Gigabit EtherChannels.

Using dual SFP module uplinks from the switches provides redundant uplinks to the network core. Using SFP modules provides flexibility in media and distance options through fiber-optic connections.

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Network Configuration Examples

Figure 1-2 Server Aggregation

Chapter 1 Overview

Campus

core

Catalyst 6500 switches

Catalyst 3750 StackWise switch stacks

Access-layer Catalyst switches

Server racks

89376

Small to Medium-Sized Network Using Catalyst 2960 Switches

Figure 1-3 shows a configuration for a network of up to 500 employees. This network uses Catalyst 2960

switches with high-speed connections to two routers. For network reliability and load balancing, this network has HSRP enabled on the routers. This ensures connectivity to the Internet, WAN, and mission-critical network resources in case one of the routers fails. The switches are using EtherChannel for load sharing.

The switches are connected to workstations, local servers, and IEEE 802.3af compliant and noncompliant powered devices (such as Cisco IP Phones). The server farm includes a call-processing server running Cisco CallManager software. Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration. The switches are interconnected through Gigabit interfaces.

This network uses VLANs to logically segment the network into well-defined broadcast groups and for security management. Data and multimedia traffic are configured on the same VLAN. Voice traffic from the Cisco IP Phones are configured on separate VVIDs. If data, multimedia, and voice traffic are assigned to the same VLAN, only one VLAN can be configured per wiring closet.

When an end station in one VLAN needs to communicate with an end station in another VLAN, a router routes the traffic to the destination VLAN. In this network, the routers are providing inter-VLAN routing. VLAN access control lists (VLAN maps) on the switch provide intra-VLAN security and prevent unauthorized users from accessing critical areas of the network.

In addition to inter-VLAN routing, the routers provide QoS mechanisms such as DSCP priorities to prioritize the different types of network traffic and to deliver high-priority traffic. If congestion occurs, QoS drops low-priority traffic to allow delivery of high-priority traffic.

For pre-standard and IEEE 802.3af-compliant powered devices connected to Catalyst PoE switches, IEEE 802.1p/Q QoS gives voice traffic forwarding-priority over data traffic.

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Chapter 1 Overview

Network Configuration Examples

Catalyst PoE switch ports automatically detect any Cisco pre-standard and IEEE 802.3af-compliant powered devices that are connected. Each PoE switch port provides 15.4 W of power per port. The powered device, such as a Cisco IP Phone, can receive redundant power when it is also connected to an AC power source. Powered devices not connected to Catalyst PoE switches must be connected to AC power sources to receive power.

Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration. Users with workstations running Cisco SoftPhone software can place, receive, and control calls from their PCs. Using Cisco IP Phones, Cisco CallManager software, and Cisco SoftPhone software integrates telephony and IP networks, and the IP network supports both voice and data.

The routers also provide firewall services, Network Address Translation (NAT) services, voice-over-IP (VoIP) gateway services, and WAN and Internet access.

Figure 1-3 Catalyst 2960 Switches in a Collapsed Backbone Configuration

Internet

Cisco 2600 or

3700 routers

IP IP

Cisco IP

phones

Workstations

running

Cisco SoftPhone

software

Aironet wireless

access points

Long-Distance, High-Bandwidth Transport Configuration

Figure 1-4 shows a configuration for sending 8 Gigabits of data over a single fiber-optic cable. The

Catalyst 2960 switches have coarse wavelength-division multiplexing (CWDM) fiber-optic SFP modules installed. Depending on the CWDM SFP module, data is sent at wavelengths from 1470 to 1610 nm. The higher the wavelength, the farther the transmission can travel. A common wavelength used for long-distance transmissions is 1550 nm.

The CWDM SFP modules connect to CWDM optical add/drop multiplexer (OADM) modules over distances of up to 393,701 feet (74.5 miles or 120 km). The CWDM OADM modules combine (or multiplex) the different CWDM wavelengths, allowing them to travel simultaneously on the same fiber-optic cable. The CWDM OADM modules on the receiving end separate (or demultiplex) the different wavelengths.

Gigabit servers

101388

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For more information about the CWDM SFP modules and CWDM OADM modules, see the Cisco CWDM GBIC and CWDM SFP Installation Note.

Catalyst 2960 Switch Software Configuration Guide

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Where to Go Next

Chapter 1 Overview

Figure 1-4 Long-Distance, High-Bandwidth Transport Configuration

Access layer

Aggregation layer

8 Gbps

Catalyst switches

Where to Go Next

Before configuring the switch, review these sections for startup information:

• Chapter 2, “Using the Command-Line Interface”

• Chapter 3, “Assigning the Switch IP Address and Default Gateway”

Eight

1-Gbps

connections

CWDM

OADM

modules

CWDM

OADM

modules

Catalyst 4500

multilayer

switches

95750

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CHAPTER

Using the Command-Line Interface

This chapter describes the Cisco IOS command-line interface (CLI) and how to use it to configure your Catalyst 2960 switch. It contains these sections:

• Understanding Command Modes, page 2-1

• Understanding the Help System, page 2-3

• Understanding Abbreviated Commands, page 2-4

• Understanding no and default Forms of Commands, page 2-4

• Understanding CLI Error Messages, page 2-5

• Using Command History, page 2-5

• Using Editing Features, page 2-6

• Searching and Filtering Output of show and more Commands, page 2-9

• Accessing the CLI, page 2-9

Understanding Command Modes

The Cisco IOS user interface is divided into many different modes. The commands available to you depend on which mode you are currently in. Enter a question mark (?) at the system prompt to obtain a list of commands available for each command mode.

When you start a session on the switch, you begin in user mode, often called user EXEC mode. Only a limited subset of the commands are available in user EXEC mode. For example, most of the user EXEC commands are one-time commands, such as show commands, which show the current configuration status, and clear commands, which clear counters or interfaces. The user EXEC commands are not saved when the switch reboots.

To have access to all commands, you must enter privileged EXEC mode. Normally, you must enter a password to enter privileged EXEC mode. From this mode, you can enter any privileged EXEC command or enter global configuration mode.

Using the configuration modes (global, interface, and line), you can make changes to the running configuration. If you save the configuration, these commands are stored and used when the switch reboots. To access the various configuration modes, you must start at global configuration mode. From global configuration mode, you can enter interface configuration mode and line configuration mode.

Table 2-1 describes the main command modes, how to access each one, the prompt you see in that mode,

and how to exit the mode. The examples in the table use the hostname Switch.

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Chapter 2 Using the Command-Line Interface

Understanding Command Modes

Table 2-1 Command Mode Summary

Mode Access Method Prompt Exit Method About This Mode

User EXEC Begin a session with

your switch.

Privileged EXEC While in user EXEC

mode, enter the enable command.

Global configuration While in privileged

EXEC mode, enter the configure command.

Config-vlan While in global

configuration mode, enter the vlan vlan-id command.

VLAN configuration While in privileged

EXEC mode, enter the vlan database command.

Switch>

Switch#

Switch(config)#

Switch(config-vlan)#

Switch(vlan)#

Enter logout or quit.

Enter disable to exit.

To exit to privileged EXEC mode, enter

exit or end, or press Ctrl-Z.

To exit to global configuration mode, enter the exit command.

To return to privileged EXEC mode, press Ctrl-Z or enter end.

To exit to privileged EXEC mode, enter exit.

Use this mode to

• Change terminal settings.

• Perform basic tests.

• Display system

information.

Use this mode to verify commands that you have entered. Use a password to protect access to this mode.

Use this mode to configure parameters that apply to the entire switch.

Use this mode to configure VLAN parameters. When VTP mode is transparent, you can create extended-range VLANs (VLAN IDs greater than 1005) and save configurations in the switch startup configuration file.

Use this mode to configure VLAN parameters for VLANs 1 to 1005 in the VLAN database.

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Understanding the Help System

Table 2-1 Command Mode Summary (continued)

Mode Access Method Prompt Exit Method About This Mode

Interface configuration

While in global configuration mode, enter the interface command (with a specific interface).

Line configuration While in global

configuration mode, specify a line with the line vty or line console command.

Switch(config-if)#

Switch(config-line)#

To exit to global configuration mode, enter exit.

To return to privileged EXEC mode, press Ctrl-Z or enter end.

To exit to global configuration mode, enter exit.

To return to privileged EXEC mode, press Ctrl-Z or enter end.

Use this mode to configure parameters for the Ethernet ports.

For information about defining interfaces, see the “Using

Interface Configuration Mode” section on page 10-4.

To configure multiple interfaces with the same parameters, see the

“Configuring a Range of Interfaces” section on page 10-6.

Use this mode to configure parameters for the terminal line.

For more detailed information on the command modes, see the command reference guide for this release.

Understanding the Help System

You can enter a question mark (?) at the system prompt to display a list of commands available for each command mode. You can also obtain a list of associated keywords and arguments for any command, as shown in Table 2-2 .

Ta b l e 2 - 2 H e l p Su m m ar y

Command Purpose

help Obtain a brief description of the help system in any command mode.

abbreviated-command-entry? Obtain a list of commands that begin with a particular character string.

For example:

Switch# di? dir disable disconnect

abbreviated-command-entry<Ta b> Complete a partial command name.

For example:

Switch# sh conf<tab> Switch# show configuration

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Understanding Abbreviated Commands

Table 2-2 Help Summary (continued)

Command Purpose

? List all commands available for a particular command mode.

For example:

Switch> ?

command ? List the associated keywords for a command.

For example:

Switch> show ?

command keyword ? List the associated arguments for a keyword.

For example:

Switch(config)# cdp holdtime ? <10-255> Length of time (in sec) that receiver must keep this packet

Understanding Abbreviated Commands

You need to enter only enough characters for the switch to recognize the command as unique.

This example shows how to enter the show configuration privileged EXEC command in an abbreviated form:

Switch# show conf

Understanding no and default Forms of Commands

Almost every configuration command also has a no form. In general, use the no form to disable a feature or function or reverse the action of a command. For example, the no shutdown interface configuration command reverses the shutdown of an interface. Use the command without the keyword no to re-enable a disabled feature or to enable a feature that is disabled by default.

Configuration commands can also have a default form. The default form of a command returns the command setting to its default. Most commands are disabled by default, so the default form is the same as the no form. However, some commands are enabled by default and have variables set to certain default values. In these cases, the default command enables the command and sets variables to their default values.

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Understanding CLI Error Messages

Table 2-3 lists some error messages that you might encounter while using the CLI to configure your

switch.

Table 2-3 Common CLI Error Messages

Error Message Meaning How to Get Help

% Ambiguous command: "show con"

% Incomplete command.

% Invalid input detected at ‘^’ marker.

You did not enter enough characters for your switch to recognize the command.

You did not enter all the keywords or values required by this command.

You entered the command incorrectly. The caret (^) marks the point of the error.

Re-enter the command followed by a question mark (?) with a space between the command and the question mark.

The possible keywords that you can enter with the command appear.

Re-enter the command followed by a question mark (?) with a space between the command and the question mark.

The possible keywords that you can enter with the command appear.

Enter a question mark (?) to display all the commands that are available in this command mode.

The possible keywords that you can enter with the command appear.

Understanding CLI Error Messages

Using Command History

The software provides a history or record of commands that you have entered. The command history feature is particularly useful for recalling long or complex commands or entries, including access lists. You can customize this feature to suit your needs as described in these sections:

• Changing the Command History Buffer Size, page 2-5 (optional)

• Recalling Commands, page 2-6 (optional)

• Disabling the Command History Feature, page 2-6 (optional)

Changing the Command History Buffer Size

By default, the switch records ten command lines in its history buffer. You can alter this number for a current terminal session or for all sessions on a particular line. These procedures are optional.

Beginning in privileged EXEC mode, enter this command to change the number of command lines that the switch records during the current terminal session:

Switch# terminal history [size

The range is from 0 to 256.

number-of-lines

]

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Using Editing Features

Beginning in line configuration mode, enter this command to configure the number of command lines the switch records for all sessions on a particular line:

Switch(config-line)# history [size

The range is from 0 to 256.

number-of-lines

]

Recalling Commands

To recall commands from the history buffer, perform one of the actions listed in Table 2 -4. These actions are optional.

Table 2-4 Recalling Commands

Action

Press Ctrl-P or the up arrow key. Recall commands in the history buffer, beginning with the most recent command.

Press Ctrl-N or the down arrow key. Return to more recent commands in the history buffer after recalling commands

show history While in privileged EXEC mode, list the last several commands that you just

1. The arrow keys function only on ANSI-compatible terminals such as VT100s.

Result

Repeat the key sequence to recall successively older commands.

with Ctrl-P or the up arrow key. Repeat the key sequence to recall successively more recent commands.

entered. The number of commands that appear is controlled by the setting of the terminal history global configuration command and the history line configuration command.

Disabling the Command History Feature

The command history feature is automatically enabled. You can disable it for the current terminal session or for the command line. These procedures are optional.

To disable the feature during the current terminal session, enter the terminal no history privileged EXEC command.

To disable command history for the line, enter the no history line configuration command.

Using Editing Features

This section describes the editing features that can help you manipulate the command line. It contains these sections:

• Enabling and Disabling Editing Features, page 2-7 (optional)

• Editing Commands through Keystrokes, page 2-7 (optional)

• Editing Command Lines that Wrap, page 2-8 (optional)

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Enabling and Disabling Editing Features

Although enhanced editing mode is automatically enabled, you can disable it, re-enable it, or configure a specific line to have enhanced editing. These procedures are optional.

To globally disable enhanced editing mode, enter this command in line configuration mode:

Switch (config-line)# no editing

To re-enable the enhanced editing mode for the current terminal session, enter this command in privileged EXEC mode:

Switch# terminal editing

To reconfigure a specific line to have enhanced editing mode, enter this command in line configuration mode:

Switch(config-line)# editing

Editing Commands through Keystrokes

Using Editing Features

Table 2-5 shows the keystrokes that you need to edit command lines. These keystrokes are optional.

Table 2-5 Editing Commands through Keystrokes

Capability Keystroke

Move around the command line to make changes or corrections.

Press Ctrl-B, or press the left arrow key.

Press Ctrl-F, or press the right arrow key.

Press Ctrl-A. Move the cursor to the beginning of the command line.

Press Ctrl-E. Move the cursor to the end of the command line.

Press Esc B. Move the cursor back one word.

Press Esc F. Move the cursor forward one word.

Press Ctrl-T. Transpose the character to the left of the cursor with the

Recall commands from the buffer

Press Ctrl-Y. Recall the most recent entry in the buffer.

and paste them in the command line. The switch provides a buffer with the last ten items that you deleted.

Press Esc Y. Recall the next buffer entry.

Delete entries if you make a mistake or change your mind.

Press the Delete or Backspace key.

Purpose

Move the cursor back one character.

Move the cursor forward one character.

character located at the cursor.

The buffer contains only the last 10 items that you have deleted or cut. If you press Esc Y more than ten times, you cycle to the first buffer entry.

Erase the character to the left of the cursor.

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Table 2-5 Editing Commands through Keystrokes (continued)

Chapter 2 Using the Command-Line Interface

Capability Keystroke

Press Ctrl-D. Delete the character at the cursor.

Press Ctrl-K. Delete all characters from the cursor to the end of the

Press Ctrl-U or Ctrl-X. Delete all characters from the cursor to the beginning of

Press Ctrl-W. Delete the word to the left of the cursor.

Press Esc D. Delete from the cursor to the end of the word.

Capitalize or lowercase words or

Press Esc C. Capitalize at the cursor.

capitalize a set of letters.

Press Esc L. Change the word at the cursor to lowercase.

Press Esc U. Capitalize letters from the cursor to the end of the word.

Designate a particular keystroke as

Press Ctrl-V or Esc Q.

an executable command, perhaps as a shortcut.

Scroll down a line or screen on

Press the Return key. Scroll down one line.

displays that are longer than the terminal screen can display.

Note The More prompt is used for

any output that has more lines than can be displayed on the terminal screen, including show command output. You can use the Return and Space bar keystrokes whenever you see the More prompt.

Press the Space bar. Scroll down one screen.

Redisplay the current command line

Press Ctrl-L or Ctrl-R. Redisplay the current command line.

if the switch suddenly sends a message to your screen.

1. The arrow keys function only on ANSI-compatible terminals such as VT100s.

Purpose

command line.

the command line.

Editing Command Lines that Wrap

You can use a wraparound feature for commands that extend beyond a single line on the screen. When the cursor reaches the right margin, the command line shifts ten spaces to the left. You cannot see the first ten characters of the line, but you can scroll back and check the syntax at the beginning of the command. The keystroke actions are optional.

To scroll back to the beginning of the command entry, press Ctrl-B or the left arrow key repeatedly. You can also press Ctrl-A to immediately move to the beginning of the line.

Note The arrow keys function only on ANSI-compatible terminals such as VT100s.

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In this example, the access-list global configuration command entry extends beyond one line. When the cursor first reaches the end of the line, the line is shifted ten spaces to the left and redisplayed. The dollar sign ($) shows that the line has been scrolled to the left. Each time the cursor reaches the end of the line, the line is again shifted ten spaces to the left.

Switch(config)# access-list 101 permit tcp 131.108.2.5 255.255.255.0 131.108.1 Switch(config)# $ 101 permit tcp 131.108.2.5 255.255.255.0 131.108.1.20 255.25 Switch(config)# $t tcp 131.108.2.5 255.255.255.0 131.108.1.20 255.255.255.0 eq Switch(config)# $108.2.5 255.255.255.0 131.108.1.20 255.255.255.0 eq 45

After you complete the entry, press Ctrl-A to check the complete syntax before pressing the Return key to execute the command. The dollar sign ($) appears at the end of the line to show that the line has been scrolled to the right:

Switch(config)# access-list 101 permit tcp 131.108.2.5 255.255.255.0 131.108.1$

The software assumes you have a terminal screen that is 80 columns wide. If you have a width other than that, use the terminal width privileged EXEC command to set the width of your terminal.

Use line wrapping with the command history feature to recall and modify previous complex command entries. For information about recalling previous command entries, see the “Editing Commands through

Keystrokes” section on page 2-7.

Searching and Filtering Output of show and more Commands

You can search and filter the output for show and more commands. This is useful when you need to sort through large amounts of output or if you want to exclude output that you do not need to see. Using these commands is optional.

To use this functionality, enter a show or more command followed by the pipe character (|), one of the keywords begin, include, or exclude, and an expression that you want to search for or filter out:

command | {begin | include | exclude} regular-expression

Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output are not displayed, but the lines that contain Output appear.

This example shows how to include in the output display only lines where the expression protocol appears:

Switch# show interfaces | include protocol Vlan1 is up, line protocol is up Vlan10 is up, line protocol is down GigabitEthernet0/1 is up, line protocol is down GigabitEthernet0/2 is up, line protocol is up

Accessing the CLI

You can access the CLI through a console connection, through Telnet, or by using the browser.

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Accessing the CLI

Accessing the CLI through a Console Connection or through Telnet

Before you can access the CLI, you must connect a terminal or PC to the switch console port and power on the switch as described in the hardware installation guide that shipped with your switch. Then, to understand the boot process and the options available for assigning IP information, see Chapter 3,

“Assigning the Switch IP Address and Default Gateway.”

If your switch is already configured, you can access the CLI through a local console connection or through a remote Telnet session, but your switch must first be configured for this type of access. For more information, see the “Setting a Telnet Password for a Terminal Line” section on page 8-6.

You can use one of these methods to establish a connection with the switch:

• Connect the switch console port to a management station or dial-up modem. For information about

connecting to the console port, see the switch hardware installation guide.

• Use any Telnet TCP/IP or encrypted Secure Shell (SSH) package from a remote management

station. The switch must have network connectivity with the Telnet or SSH client, and the switch must have an enable secret password configured.

For information about configuring the switch for Telnet access, see the “Setting a Telnet Password

for a Terminal Line” section on page 8-6. The switch supports up to 16 simultaneous Telnet sessions.

Changes made by one Telnet user are reflected in all other Telnet sessions.

For information about configuring the switch for SSH, see the “Configuring the Switch for Secure

Shell” section on page 8-33. The switch supports up to five simultaneous secure SSH sessions.

After you connect through the console port, through a Telnet session or through an SSH session, the user EXEC prompt appears on the management station.

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CHAPTER

Assigning the Switch IP Address and Default Gateway

This chapter describes how to create the initial switch configuration (for example, assigning the switch IP address and default gateway information) for the Catalyst 2960 switch by using a variety of automatic and manual methods. It also describes how to modify the switch startup configuration.

Note For complete syntax and usage information for the commands used in this chapter, see the command

reference for this release and to the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services, Release 12.2.

This chapter consists of these sections:

• Understanding the Boot Process, page 3-1

• Assigning Switch Information, page 3-2

• Checking and Saving the Running Configuration, page 3-10

• Modifying the Startup Configuration, page 3-11

• Scheduling a Reload of the Software Image, page 3-15

Understanding the Boot Process

To start your switch, you need to follow the procedures in the hardware installation guide about installing and powering on the switch, and setting up the initial configuration (IP address, subnet mask, default gateway, secret and Telnet passwords, and so forth) of the switch.

The normal boot process involves the operation of the boot loader software, which performs these activities:

• Performs low-level CPU initialization. It initializes the CPU registers, which control where physical

memory is mapped, its quantity, its speed, and so forth.

• Performs power-on self-test (POST) for the CPU subsystem. It tests the CPU DRAM and the portion

of the flash device that makes up the flash file system.

• Initializes the flash file system on the system board.

• Loads a default operating system software image into memory and boots the switch.

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Assigning Switch Information

The boot loader provides access to the flash file system before the operating system is loaded. Normally, the boot loader is used only to load, uncompress, and launch the operating system. After the boot loader gives the operating system control of the CPU, the boot loader is not active until the next system reset or power-on.

The boot loader also provides trap-door access into the system if the operating system has problems serious enough that it cannot be used. The trap-door mechanism provides enough access to the system so that if it is necessary, you can format the flash file system, reinstall the operating system software image by using the Xmodem Protocol, recover from a lost or forgotten password, and finally restart the operating system. For more information, see the “Recovering from a Software Failure” section on

page 31-2 and the “Recovering from a Lost or Forgotten Password” section on page 31-3.

Note You can disable password recovery. For more information, see the “Disabling Password Recovery”

section on page 8-5.

Before you can assign switch information, make sure you have connected a PC or terminal to the console port, and configured the PC or terminal-emulation software baud rate and character format to match these of the switch console port:

• Baud rate default is 9600.

Chapter 3 Assigning the Switch IP Address and Default Gateway

• Data bits default is 8.

Note If the data bits option is set to 8, set the parity option to none.

• Stop bits default is 1.

• Parity settings default is none.

Assigning Switch Information

You can assign IP information through the switch setup program, through a DHCP server, or manually.

Use the switch setup program if you want to be prompted for specific IP information. With this program, you can also configure a hostname and an enable secret password. It gives you the option of assigning a Telnet password (to provide security during remote management) and configuring your switch as a command or member switch of a cluster or as a standalone switch. For more information about the setup program, see the hardware installation guide.

Use a DHCP server for centralized control and automatic assignment of IP information after the server is configured.

Note If you are using DHCP, do not respond to any of the questions in the setup program until the switch

receives the dynamically assigned IP address and reads the configuration file.

3-2

If you are an experienced user familiar with the switch configuration steps, manually configure the switch. Otherwise, use the setup program described previously.

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These sections contain this configuration information:

• Default Switch Information, page 3-3

• Understanding DHCP-Based Autoconfiguration, page 3-3

• Manually Assigning IP Information, page 3-9

Default Switch Information

Table 3-1 shows the default switch information.

Table 3-1 Default Switch Information

Feature Default Setting

IP address and subnet mask No IP address or subnet mask are defined.

Default gateway No default gateway is defined.

Enable secret password No password is defined.

Hostname The factory-assigned default hostname is Switch.

Telnet password No password is defined.

Cluster command switch functionality Disabled.

Cluster name No cluster name is defined.

Assigning Switch Information

Understanding DHCP-Based Autoconfiguration

DHCP provides configuration information to Internet hosts and internetworking devices. This protocol consists of two components: one for delivering configuration parameters from a DHCP server to a device and a mechanism for allocating network addresses to devices. DHCP is built on a client-server model, in which designated DHCP servers allocate network addresses and deliver configuration parameters to dynamically configured devices. The switch can act as both a DHCP client and a DHCP server.

During DHCP-based autoconfiguration, your switch (DHCP client) is automatically configured at startup with IP address information and a configuration file.

With DHCP-based autoconfiguration, no DHCP client-side configuration is needed on your switch. However, you need to configure the DHCP server for various lease options associated with IP addresses. If you are using DHCP to relay the configuration file location on the network, you might also need to configure a Trivial File Transfer Protocol (TFTP) server and a Domain Name System (DNS) server.

The DHCP server for your switch can be on the same LAN or on a different LAN than the switch. If the DHCP server is running on a different LAN, you should configure a DHCP relay device between your switch and the DHCP server. A relay device forwards broadcast traffic between two directly connected LANs. A router does not forward broadcast packets, but it forwards packets based on the destination IP address in the received packet.

DHCP-based autoconfiguration replaces the BOOTP client functionality on your switch.

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DHCP Client Request Process

When you boot your switch, the DHCP client is invoked and requests configuration information from a DHCP server when the configuration file is not present on the switch. If the configuration file is present and the configuration includes the ip address dhcp interface configuration command on specific routed interfaces, the DHCP client is invoked and requests the IP address information for those interfaces.

Figure 3-1 shows the sequence of messages that are exchanged between the DHCP client and the DHCP

server.

Figure 3-1 DHCP Client and Server Message Exchange

Switch A

The client, Switch A, broadcasts a DHCPDISCOVER message to locate a DHCP server. The DHCP server offers configuration parameters (such as an IP address, subnet mask, gateway IP address, DNS IP address, a lease for the IP address, and so forth) to the client in a DHCPOFFER unicast message.

DHCPDISCOVER (broadcast)

DHCPOFFER (unicast)

DHCPREQUEST (broadcast)

DHCPACK (unicast)

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DHCP server

51807

In a DHCPREQUEST broadcast message, the client returns a formal request for the offered configuration information to the DHCP server. The formal request is broadcast so that all other DHCP servers that received the DHCPDISCOVER broadcast message from the client can reclaim the IP addresses that they offered to the client.

The DHCP server confirms that the IP address has been allocated to the client by returning a DHCPACK unicast message to the client. With this message, the client and server are bound, and the client uses configuration information received from the server. The amount of information the switch receives depends on how you configure the DHCP server. For more information, see the “Configuring the TFTP

Server” section on page 3-5.

If the configuration parameters sent to the client in the DHCPOFFER unicast message are invalid (a configuration error exists), the client returns a DHCPDECLINE broadcast message to the DHCP server.

The DHCP server sends the client a DHCPNAK denial broadcast message, which means that the offered configuration parameters have not been assigned, that an error has occurred during the negotiation of the parameters, or that the client has been slow in responding to the DHCPOFFER message (the DHCP server assigned the parameters to another client).

A DHCP client might receive offers from multiple DHCP or BOOTP servers and can accept any of the offers; however, the client usually accepts the first offer it receives. The offer from the DHCP server is not a guarantee that the IP address is allocated to the client; however, the server usually reserves the address until the client has had a chance to formally request the address. If the switch accepts replies from a BOOTP server and configures itself, the switch broadcasts, instead of unicasts, TFTP requests to obtain the switch configuration file.

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Configuring DHCP-Based Autoconfiguration

These sections contain this configuration information:

• DHCP Server Configuration Guidelines, page 3-5

• Configuring the TFTP Server, page 3-5

• Configuring the DNS, page 3-6

• Configuring the Relay Device, page 3-6

• Obtaining Configuration Files, page 3-7

• Example Configuration, page 3-8

If your DHCP server is a Cisco device, see the “Configuring DHCP” section of the “IP Addressing and Services” section of the Cisco IOS IP Configuration Guide, Release 12.2 for additional information about configuring DHCP.

DHCP Server Configuration Guidelines

Follow these guidelines if you are configuring a device as a DHCP server:

Assigning Switch Information

You should configure the DHCP server with reserved leases that are bound to each switch by the switch hardware address.

If you want the switch to receive IP address information, you must configure the DHCP server with these lease options:

• IP address of the client (required)

• Subnet mask of the client (required)

• DNS server IP address (optional)

• Router IP address (default gateway address to be used by the switch) (required)

If you want the switch to receive the configuration file from a TFTP server, you must configure the DHCP server with these lease options:

• TFTP server name (required)

• Boot filename (the name of the configuration file that the client needs) (recommended)

• Hostname (optional)

Depending on the settings of the DHCP server, the switch can receive IP address information, the configuration file, or both.

If you do not configure the DHCP server with the lease options described previously, it replies to client requests with only those parameters that are configured. If the IP address and the subnet mask are not in the reply, the switch is not configured. If the router IP address or the TFTP server name are not found, the switch might send broadcast, instead of unicast, TFTP requests. Unavailability of other lease options does not affect autoconfiguration.

Configuring the TFTP Server

Based on the DHCP server configuration, the switch attempts to download one or more configuration files from the TFTP server. If you configured the DHCP server to respond to the switch with all the options required for IP connectivity to the TFTP server, and if you configured the DHCP server with a TFTP server name, address, and configuration filename, the switch attempts to download the specified configuration file from the specified TFTP server.

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Assigning Switch Information

If you did not specify the configuration filename, the TFTP server, or if the configuration file could not be downloaded, the switch attempts to download a configuration file by using various combinations of filenames and TFTP server addresses. The files include the specified configuration filename (if any) and these files: network-config, cisconet.cfg, hostname.config, or hostname.cfg, where hostname is the switch’s current hostname. The TFTP server addresses used include the specified TFTP server address (if any) and the broadcast address (255.255.255.255).

For the switch to successfully download a configuration file, the TFTP server must contain one or more configuration files in its base directory. The files can include these files:

• The configuration file named in the DHCP reply (the actual switch configuration file).

• The network-confg or the cisconet.cfg file (known as the default configuration files).

• The router-confg or the ciscortr.cfg file (These files contain commands common to all switches.

If you specify the TFTP server name in the DHCP server-lease database, you must also configure the TFTP server name-to-IP-address mapping in the DNS-server database.

If the TFTP server to be used is on a different LAN from the switch, or if it is to be accessed by the switch through the broadcast address (which occurs if the DHCP server response does not contain all the required information described previously), a relay must be configured to forward the TFTP packets to the TFTP server. For more information, see the “Configuring the Relay Device” section on page 3-6. The preferred solution is to configure the DHCP server with all the required information.

Chapter 3 Assigning the Switch IP Address and Default Gateway

Normally, if the DHCP and TFTP servers are properly configured, these files are not accessed.)

Configuring the DNS

The DHCP server uses the DNS server to resolve the TFTP server name to an IP address. You must configure the TFTP server name-to-IP address map on the DNS server. The TFTP server contains the configuration files for the switch.

You can configure the IP addresses of the DNS servers in the lease database of the DHCP server from where the DHCP replies will retrieve them. You can enter up to two DNS server IP addresses in the lease database.

The DNS server can be on the same or on a different LAN as the switch. If it is on a different LAN, the switch must be able to access it through a router.

Configuring the Relay Device

You must configure a relay device, also referred to as a relay agent, when a switch sends broadcast packets that require a response from a host on a different LAN. Examples of broadcast packets that the switch might send are DHCP, DNS, and in some cases, TFTP packets. You must configure this relay device to forward received broadcast packets on an interface to the destination host.

If the relay device is a Cisco router, enable IP routing (ip routing global configuration command), and configure helper addresses by using the ip helper-address interface configuration command.

For example, in Figure 3-2, configure the router interfaces as follows:

On interface 10.0.0.2:

router(config-if)# ip helper-address 20.0.0.2 router(config-if)# ip helper-address 20.0.0.3 router(config-if)# ip helper-address 20.0.0.4

3-6

On interface 20.0.0.1

router(config-if)# ip helper-address 10.0.0.1

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Figure 3-2 Relay Device Used in Autoconfiguration

Assigning Switch Information

Switch

(DHCP client)

10.0.0.1

20.0.0.2 20.0.0.3

DHCP server TFTP server DNS server

Obtaining Configuration Files

Depending on the availability of the IP address and the configuration filename in the DHCP reserved lease, the switch obtains its configuration information in these ways:

• The IP address and the configuration filename is reserved for the switch and provided in the DHCP

reply (one-file read method).

The switch receives its IP address, subnet mask, TFTP server address, and the configuration filename from the DHCP server. The switch sends a unicast message to the TFTP server to retrieve the named configuration file from the base directory of the server and upon receipt, it completes its boot-up process.

Cisco router

(Relay)

10.0.0.2

20.0.0.1

20.0.0.4

49068

• The IP address and the configuration filename is reserved for the switch, but the TFTP server

address is not provided in the DHCP reply (one-file read method).

The switch receives its IP address, subnet mask, and the configuration filename from the DHCP server. The switch sends a broadcast message to a TFTP server to retrieve the named configuration file from the base directory of the server, and upon receipt, it completes its boot-up process.

• Only the IP address is reserved for the switch and provided in the DHCP reply. The configuration

filename is not provided (two-file read method).

The switch receives its IP address, subnet mask, and the TFTP server address from the DHCP server. The switch sends a unicast message to the TFTP server to retrieve the network-confg or cisconet.cfg default configuration file. (If the network-confg file cannot be read, the switch reads the cisconet.cfg file.)

The default configuration file contains the hostnames-to-IP-address mapping for the switch. The switch fills its host table with the information in the file and obtains its hostname. If the hostname is not found in the file, the switch uses the hostname in the DHCP reply. If the hostname is not specified in the DHCP reply, the switch uses the default Switch as its hostname.

After obtaining its hostname from the default configuration file or the DHCP reply, the switch reads the configuration file that has the same name as its hostname (hostname-confg or hostname.cfg, depending on whether network-confg or cisconet.cfg was read earlier) from the TFTP server. If the cisconet.cfg file is read, the filename of the host is truncated to eight characters.

If the switch cannot read the network-confg, cisconet.cfg, or the hostname file, it reads the router-confg file. If the switch cannot read the router-confg file, it reads the ciscortr.cfg file.

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Assigning Switch Information

Note The switch broadcasts TFTP server requests if the TFTP server is not obtained from the DHCP replies,

if all attempts to read the configuration file through unicast transmissions fail, or if the TFTP server name cannot be resolved to an IP address.

Example Configuration

Figure 3-3 shows a sample network for retrieving IP information by using DHCP-based autoconfiguration.

Figure 3-3 DHCP-Based Autoconfiguration Network Example

Chapter 3 Assigning the Switch IP Address and Default Gateway

Switch 1

00e0.9f1e.2001

Cisco router

10.0.0.10

DHCP server DNS server TFTP server

Switch 2

00e0.9f1e.2002

10.0.0.1

Switch 3

00e0.9f1e.2003

10.0.0.2 10.0.0.3

(tftpserver)

Switch 4

00e0.9f1e.2004

111394

Table 3-2 shows the configuration of the reserved leases on the DHCP server.

Table 3-2 DHCP Server Configuration

Switch A Switch B Switch C Switch D

Binding key (hardware address) 00e0.9f1e.2001 00e0.9f1e.2002 00e0.9f1e.2003 00e0.9f1e.2004

IP address 10.0.0.21 10.0.0.22 10.0.0.23 10.0.0.24

Subnet mask 255.255.255.0 255.255.255.0 255.255.255.0 255.255.255.0

Router address 10.0.0.10 10.0.0.10 10.0.0.10 10.0.0.10

DNS server address 10.0.0.2 10.0.0.2 10.0.0.2 10.0.0.2

TFTP server name tftpserver or

10.0.0.3

Boot filename (configuration file)

switcha-confg switchb-confg switchc-confg switchd-confg

tftpserver or

10.0.0.3

tftpserver or

10.0.0.3

tftpserver or

10.0.0.3

(optional)

Hostname (optional) switcha switchb switchc switchd

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DNS Server Configuration

The DNS server maps the TFTP server name tftpserver to IP address 10.0.0.3.

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TFTP Server Configuration (on UNIX)

The TFTP server base directory is set to /tftpserver/work/. This directory contains the network-confg file used in the two-file read method. This file contains the hostname to be assigned to the switch based on its IP address. The base directory also contains a configuration file for each switch (switcha-confg, switchb-confg, and so forth) as shown in this display:

prompt> cd /tftpserver/work/ prompt> ls network-confg switcha-confg switchb-confg switchc-confg switchd-confg prompt> cat network-confg ip host switcha 10.0.0.21 ip host switchb 10.0.0.22 ip host switchc 10.0.0.23 ip host switchd 10.0.0.24

DHCP Client Configuration

No configuration file is present on Switch A through Switch D.

Assigning Switch Information

Configuration Explanation

In Figure 3-3, Switch A reads its configuration file as follows:

• It obtains its IP address 10.0.0.21 from the DHCP server.

• If no configuration filename is given in the DHCP server reply, Switch A reads the network-confg

file from the base directory of the TFTP server.

• It adds the contents of the network-confg file to its host table.

• It reads its host table by indexing its IP address 10.0.0.21 to its hostname (switcha).

• It reads the configuration file that corresponds to its hostname; for example, it reads switch1-confg

from the TFTP server.

Switches B through D retrieve their configuration files and IP addresses in the same way.

Manually Assigning IP Information

Beginning in privileged EXEC mode, follow these steps to manually assign IP information to multiple switched virtual interfaces (SVIs):

Command Purpose

Step 1

Step 2

Step 3

Step 4

configure terminal Enter global configuration mode.

interface vlan vlan-id Enter interface configuration mode, and enter the VLAN to which the IP

information is assigned. The range is 1 to 4094.

ip address ip-address subnet-mask Enter the IP address and subnet mask.

exit Return to global configuration mode.

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Checking and Saving the Running Configuration

Command Purpose

Step 5

Step 6

Step 7

Step 8

Step 9

ip default-gateway ip-address Enter the IP address of the next-hop router interface that is directly

end Return to privileged EXEC mode.

show interfaces vlan vlan-id Verify the configured IP address.

show ip redirects Verify the configured default gateway.

copy running-config startup-config (Optional) Save your entries in the configuration file.

To remove the switch IP address, use the no ip address interface configuration command. If you are removing the address through a Telnet session, your connection to the switch will be lost. To remove the default gateway address, use the no ip default-gateway global configuration command.

Chapter 3 Assigning the Switch IP Address and Default Gateway

connected to the switch where a default gateway is being configured. The default gateway receives IP packets with unresolved destination IP addresses from the switch.

Once the default gateway is configured, the switch has connectivity to the remote networks with which a host needs to communicate.

Note When your switch is configured to route with IP, it does not need

to have a default gateway set.

For information on setting the switch system name, protecting access to privileged EXEC commands, and setting time and calendar services, see Chapter 6, “Administering the Switch.”

Checking and Saving the Running Configuration

You can check the configuration settings you entered or changes you made by entering this privileged EXEC command:

Switch# show running-config Building configuration...

Current configuration: 1363 bytes ! version 12.1 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Switch A ! enable secret 5 $1$ej9.$DMUvAUnZOAmvmgqBEzIxE0 ! . <output truncated> . interface gigabitethernet0/1 ip address 172.20.137.50 255.255.255.0 ! interface gigabitethernet0/2 mvr type source

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...! interface VLAN1

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ip address 172.20.137.50 255.255.255.0 no ip directed-broadcast ! ip default-gateway 172.20.137.1 ! ! snmp-server community private RW snmp-server community public RO snmp-server community private@es0 RW snmp-server community public@es0 RO snmp-server chassis-id 0x12 ! end

To store the configuration or changes you have made to your startup configuration in flash memory, enter this privileged EXEC command:

Switch# copy running-config startup-config Destination filename [startup-config]? Building configuration...

This command saves the configuration settings that you made. If you fail to do this, your configuration will be lost the next time you reload the system. To display information stored in the NVRAM section of flash memory, use the show startup-config or more startup-config privileged EXEC command.

Modifying the Startup Configuration

For more information about alternative locations from which to copy the configuration file, see

Appendix B, “Working with the Cisco IOS File System, Configuration Files, and Software Images.”

Modifying the Startup Configuration

These sections describe how to modify the switch startup configuration:

• Default Boot Configuration, page 3-12

• Automatically Downloading a Configuration File, page 3-12

• Booting Manually, page 3-13

• Booting a Specific Software Image, page 3-13

• Controlling Environment Variables, page 3-14

See also Appendix B, “Working with the Cisco IOS File System, Configuration Files, and Software

Images,” for information about switch configuration files.

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Modifying the Startup Configuration

Default Boot Configuration

Table 3-3 shows the default boot configuration.

Table 3-3 Default Boot Configuration

Feature Default Setting

Operating system software image The switch attempts to automatically boot the system using information in the BOOT

environment variable. If the variable is not set, the switch attempts to load and execute the first executable image it can by performing a recursive, depth-first search throughout the flash file system.

The Cisco IOS image is stored in a directory that has the same name as the image file (excluding the .bin extension).

In a depth-first search of a directory, each encountered subdirectory is completely searched before continuing the search in the original directory.

Configuration file Configured switches use the config.text file stored on the system board in flash

memory.

A new switch has no configuration file.

Automatically Downloading a Configuration File

You can automatically download a configuration file to your switch by using the DHCP-based autoconfiguration feature. For more information, see the “Understanding DHCP-Based

Autoconfiguration” section on page 3-3.

Specifying the Filename to Read and Write the System Configuration

By default, the Cisco IOS software uses the file config.text to read and write a nonvolatile copy of the system configuration. However, you can specify a different filename, which will be loaded during the next boot cycle.

Beginning in privileged EXEC mode, follow these steps to specify a different configuration filename:

Command Purpose

Step 1

Step 2

configure terminal Enter global configuration mode.

boot config-file flash:/file-url Specify the configuration file to load during the next boot cycle.

For file-url, specify the path (directory) and the configuration filename.

Step 3

Step 4

Step 5

3-12

Filenames and directory names are case sensitive.

end Return to privileged EXEC mode.

show boot Verify your entries.

The boot config-file global configuration command changes the setting of the CONFIG_FILE environment variable.

copy running-config startup-config (Optional) Save your entries in the configuration file.

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To return to the default setting, use the no boot config-file global configuration command.

Booting Manually

By default, the switch automatically boots; however, you can configure it to manually boot.

Beginning in privileged EXEC mode, follow these steps to configure the switch to manually boot during the next boot cycle:

Command Purpose

Step 1

Step 2

Step 3

Step 4

configure terminal Enter global configuration mode.

boot manual Enable the switch to manually boot during the next boot cycle.

end Return to privileged EXEC mode.

show boot Verify your entries.

Modifying the Startup Configuration

The boot manual global command changes the setting of the MANUAL_BOOT environment variable.

Step 5

copy running-config startup-config (Optional) Save your entries in the configuration file.

To disable manual booting, use the no boot manual global configuration command.

Booting a Specific Software Image

By default, the switch attempts to automatically boot the system using information in the BOOT environment variable. If this variable is not set, the switch attempts to load and execute the first executable image it can by performing a recursive, depth-first search throughout the flash file system. In a depth-first search of a directory, each encountered subdirectory is completely searched before continuing the search in the original directory. However, you can specify a specific image to boot.

Beginning in privileged EXEC mode, follow these steps to configure the switch to boot a specific image during the next boot cycle:

The next time you reboot the system, the switch is in boot loader mode, shown by the switch: prompt. To boot the system, use the boot filesystem:/file-url boot loader command.

• For filesystem:, use flash: for the system board flash device.

• For file-url, specify the path (directory) and the name of the

bootable image.

Filenames and directory names are case sensitive.

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Modifying the Startup Configuration

Command Purpose

Step 1

Step 2

Step 3

Step 4

Step 5

configure terminal Enter global configuration mode.

boot system filesystem:/file-url Configure the switch to boot a specific image in flash memory during the

end Return to privileged EXEC mode.

show boot Verify your entries.

copy running-config startup-config (Optional) Save your entries in the configuration file.

Chapter 3 Assigning the Switch IP Address and Default Gateway

next boot cycle.

• For filesystem:, use flash: for the system board flash device.

• For file-url, specify the path (directory) and the name of the bootable

image.

Filenames and directory names are case sensitive.

The boot system global command changes the setting of the BOOT environment variable.

During the next boot cycle, the switch attempts to automatically boot the system using information in the BOOT environment variable.

To return to the default setting, use the no boot system global configuration command.

Controlling Environment Variables

With a normally operating switch, you enter the boot loader mode only through a switch console connection configured for 9600 bps. Unplug the switch power cord, and press the switch Mode button while reconnecting the power cord. You can release the Mode button a second or two after the LED above port 1 turns off. Then the boot loader switch: prompt appears.

The switch boot loader software provides support for nonvolatile environment variables, which can be used to control how the boot loader, or any other software running on the system, behaves. Boot loader environment variables are similar to environment variables that can be set on UNIX or DOS systems.

Environment variables that have values are stored in flash memory outside of the flash file system.

Each line in these files contains an environment variable name and an equal sign followed by the value of the variable. A variable has no value if it is not listed in this file; it has a value if it is listed in the file even if the value is a null string. A variable that is set to a null string (for example, “ ”) is a variable with a value. Many environment variables are predefined and have default values.

Environment variables store two kinds of data:

• Data that controls code, which does not read the Cisco IOS configuration file. For example, the name

of a boot loader helper file, which extends or patches the functionality of the boot loader can be stored as an environment variable.

• Data that controls code, which is responsible for reading the Cisco IOS configuration file. For

example, the name of the Cisco IOS configuration file can be stored as an environment variable.

3-14

You can change the settings of the environment variables by accessing the boot loader or by using Cisco IOS commands. Under normal circumstances, it is not necessary to alter the setting of the environment variables.

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Scheduling a Reload of the Software Image

Note For complete syntax and usage information for the boot loader commands and environment variables,

see the command reference for this release.

Table 3-4 describes the function of the most common environment variables.

Table 3-4 Environment Variables

Variable Boot Loader Command Cisco IOS Global Configuration Command

BOOT set BOOT filesystem:/file-url ...

boot system filesystem:/file-url ...

A semicolon-separated list of executable files to try to load and execute when automatically booting. If the BOOT environment variable is not set, the system attempts to load and execute the first executable image it can find by using a recursive, depth-first search through the flash file system. If the BOOT variable is set but the specified images cannot be loaded, the system attempts to boot the first bootable file that it can find in the flash file system.

MANUAL_BOOT set MANUAL_BOOT yes

Decides whether the switch automatically or manually boots.

Valid values are 1, yes, 0, and no. If it is set to no or 0, the boot loader attempts to automatically boot the system. If it is set to anything else, you must manually boot the switch from the boot loader mode.

CONFIG_FILE set CONFIG_FILE flash:/file-url

Changes the filename that Cisco IOS uses to read and write a nonvolatile copy of the system configuration.

Specifies the Cisco IOS image to load during the next boot cycle. This command changes the setting of the BOOT environment variable.

boot manual

Enables manually booting the switch during the next boot cycle and changes the setting of the MANUAL_BOOT environment variable.

The next time you reboot the system, the switch is in boot loader mode. To boot the system, use the boot flash:filesystem:/file-url boot loader command, and specify the name of the bootable image.

boot config-file flash:/file-url

Specifies the filename that Cisco IOS uses to read and write a nonvolatile copy of the system configuration. This command changes the CONFIG_FILE environment variable.

Scheduling a Reload of the Software Image

You can schedule a reload of the software image to occur on the switch at a later time (for example, late at night or during the weekend when the switch is used less), or you can synchronize a reload network-wide (for example, to perform a software upgrade on all switches in the network).

Note A scheduled reload must take place within approximately 24 days.

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Scheduling a Reload of the Software Image

Configuring a Scheduled Reload

To configure your switch to reload the software image at a later time, use one of these commands in privileged EXEC mode:

• reload in [hh:]mm [text]

This command schedules a reload of the software to take affect in the specified minutes or hours and minutes. The reload must take place within approximately 24 days. You can specify the reason for the reload in a string up to 255 characters in length.

• reload at hh:mm [month day | day month] [text]

This command schedules a reload of the software to take place at the specified time (using a 24-hour clock). If you specify the month and day, the reload is scheduled to take place at the specified time and date. If you do not specify the month and day, the reload takes place at the specified time on the current day (if the specified time is later than the current time) or on the next day (if the specified time is earlier than the current time). Specifying 00:00 schedules the reload for midnight.

Note Use the at keyword only if the switch system clock has been set (through Network Time

Protocol (NTP), the hardware calendar, or manually). The time is relative to the configured time zone on the switch. To schedule reloads across several switches to occur simultaneously, the time on each switch must be synchronized with NTP.

Chapter 3 Assigning the Switch IP Address and Default Gateway

The reload command halts the system. If the system is not set to manually boot, it reboots itself. Use the reload command after you save the switch configuration information to the startup configuration (copy running-config startup-config).

If your switch is configured for manual booting, do not reload it from a virtual terminal. This restriction prevents the switch from entering the boot loader mode and thereby taking it from the remote user’s control.

If you modify your configuration file, the switch prompts you to save the configuration before reloading. During the save operation, the system requests whether you want to proceed with the save if the CONFIG_FILE environment variable points to a startup configuration file that no longer exists. If you proceed in this situation, the system enters setup mode upon reload.

This example shows how to reload the software on the switch on the current day at 7:30 p.m:

Switch# reload at 19:30 Reload scheduled for 19:30:00 UTC Wed Jun 5 1996 (in 2 hours and 25 minutes) Proceed with reload? [confirm]

This example shows how to reload the software on the switch at a future time:

Switch# reload at 02:00 jun 20 Reload scheduled for 02:00:00 UTC Thu Jun 20 1996 (in 344 hours and 53 minutes) Proceed with reload? [confirm]

To cancel a previously scheduled reload, use the reload cancel privileged EXEC command.

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Displaying Scheduled Reload Information

To display information about a previously scheduled reload or to find out if a reload has been scheduled on the switch, use the show reload privileged EXEC command.

It displays reload information including the time the reload is scheduled to occur and the reason for the reload (if it was specified when the reload was scheduled).

Scheduling a Reload of the Software Image

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Scheduling a Reload of the Software Image

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CHAPTER

Configuring IE2100 CNS Agents

This chapter describes how to configure the Intelligence Engine 2100 (IE2100) Series Cisco Networking Services (CNS) embedded agents on your Catalyst 2960 switch.

Note For complete syntax and usage information for the commands used in this section, see the Cisco

Intelligence Engine 2100 Series Configuration Registrar Manual, and select Cisco IOS Software

Release 12.2 > New Feature Documentation > 12.2(2)T on Cisco.com.

This chapter consists of these sections:

• Understanding IE2100 Series Configuration Registrar Software, page 4-1

• Understanding CNS Embedded Agents, page 4-5

• Configuring CNS Embedded Agents, page 4-6

• Displaying CNS Configuration, page 4-13

Understanding IE2100 Series Configuration Registrar Software

The IE2100 Series Configuration Registrar is a network management device that acts as a configuration service for automating the deployment and management of network devices and services (see Figure 4-1). Each Configuration Registrar manages a group of Cisco IOS devices (switches and routers) and the services that they deliver, storing their configurations and delivering them as needed. The Configuration Registrar automates initial configurations and configuration updates by generating device-specific configuration changes, sending them to the device, executing the configuration change, and logging the results.

The Configuration Registrar supports standalone and server modes and has these CNS components:

• Configuration service (web server, file manager, and namespace mapping server)

• Event service (event gateway)

• Data service directory (data models and schema)

In standalone mode, the Configuration Registrar supports an embedded CNS Directory Service. In this mode, no external directory or other data store is required. In server mode, the Configuration Registrar supports the use of a user-defined external directory.

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Understanding IE2100 Series Configuration Registrar Software

Figure 4-1 Configuration Registrar Architectural Overview

Service provider network

Chapter 4 Configuring IE2100 CNS Agents

Configuration

registrar

Data service directory

Configuration server

Event service

Web-based user interface

Order entry

configuration management

These sections contain this conceptual information:

• CNS Configuration Service, page 4-2

• CNS Event Service, page 4-3

• What You Should Know About ConfigID, DeviceID, and Hostname, page 4-3

71444

CNS Configuration Service

The CNS Configuration Service is the core component of the Configuration Registrar. It consists of a configuration server that works with CNS configuration agents located on the switch. The CNS Configuration Service delivers device and service configurations to the switch for initial configuration and mass reconfiguration by logical groups. Switches receive their initial configuration from the CNS Configuration Service when they start up on the network for the first time.

The CNS Configuration Service uses the CNS Event Service to send and receive configuration change events and to send success and failure notifications.

The configuration server is a web server that uses configuration templates and the device-specific configuration information stored in the embedded (standalone mode) or remote (server mode) directory.

Configuration templates are text files containing static configuration information in the form of CLI commands. In the templates, variables are specified using lightweight directory access protocol (LDAP) URLs that reference the device-specific configuration information stored in a directory.

The configuration agent can perform a syntax check on received configuration files and publish events to indicate the success or failure of the syntax check. The configuration agent can either apply configurations immediately or delay the application until receipt of a synchronization event from the configuration server.

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CNS Event Service

The Configuration Registrar uses the CNS Event Service for receipt and generation of configuration events. The CNS event agent resides on the switch and facilitates the communication between the switch and the event gateway on the Configuration Registrar.

The CNS Event Service is a highly capable publish-and-subscribe communication method. The CNS Event Service uses subject-based addressing to send messages to their destinations. Subject-based addressing conventions define a simple, uniform namespace for messages and their destinations.

NameSpace Mapper

The Configuration Registrar includes the NameSpace Mapper (NSM) that provides a lookup service for managing logical groups of devices based on application, device ID or group ID, and event.

Cisco IOS devices recognize only event subject-names that match those configured in Cisco IOS software; for example, cisco.cns.config.load. You can use the namespace mapping service to designate events by using any desired naming convention. When you have populated your data store with your subject names, NSM resolves your event subject-name strings to those known by IOS.

For a subscriber, when given a unique device ID and event, the namespace mapping service returns a set of events to which to subscribe. Similarly, for a publisher, when given a unique group ID, device ID, and event, the mapping service returns a set of events on which to publish.

Understanding IE2100 Series Configuration Registrar Software

What You Should Know About ConfigID, DeviceID, and Hostname

The Configuration Registrar assumes that a unique identifier is associated with each configured switch. This unique identifier can take on multiple synonyms, where each synonym is unique within a particular namespace. The event service uses namespace content for subject-based addressing of messages.

The Configuration Registrar intersects two namespaces, one for the event bus and the other for the configuration server. Within the scope of the configuration server namespace, the term configID is the unique identifier for a device. Within the scope of the event bus namespace, the term deviceID is the CNS unique identifier for a device.

Because the Configuration Registrar uses both the event bus and the configuration server to provide configurations to devices, you must define both configID and deviceID for each configured switch.

Within the scope of a single instance of the configuration server, no two configured switches can share the same value for configID. Within the scope of a single instance of the event bus, no two configured switches can share the same value for deviceID.

ConfigID

Each configured switch has a unique configID, which serves as the key into the Configuration Registrar directory for the corresponding set of switch CLI attributes. The configID defined on the switch must match the configID for the corresponding switch definition on the Configuration Registrar.

The configID is fixed at boot time and cannot be changed until reboot, even when the switch hostname is reconfigured.

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Understanding IE2100 Series Configuration Registrar Software

DeviceID

Each configured switch participating on the event bus has a unique deviceID, which is analogous to the switch source address so that the switch can be targeted as a specific destination on the bus. All switches configured with the cns config partial global configuration command must access the event bus. Therefore, the deviceID, as originated on the switch, must match the deviceID of the corresponding switch definition in the Configuration Registrar.

The origin of the deviceID is defined by the Cisco IOS hostname of the switch. However, the deviceID variable and its usage reside within the event gateway, which is adjacent to the switch.

The logical Cisco IOS termination point on the event bus is embedded in the event gateway, which in turn functions as a proxy on behalf of the switch. The event gateway represents the switch and its corresponding deviceID to the event bus.

The switch declares its hostname to the event gateway immediately after the successful connection to the event gateway. The event gateway couples the deviceID value to the Cisco IOS hostname each time this connection is established. The event gateway caches this deviceID value for the duration of its connection to the switch.

Hostname and DeviceID

Chapter 4 Configuring IE2100 CNS Agents

The deviceID is fixed at the time of the connection to the event gateway and does not change even when the switch hostname is reconfigured.

When changing the switch hostname on the switch, the only way to refresh the deviceID is to break the connection between the switch and the event gateway. Enter the no cns event global configuration command followed by the cns event global configuration command.

When the connection is re-established, the switch sends its modified hostname to the event gateway. The event gateway redefines the deviceID to the new value.

Caution When using the Configuration Registrar user interface, you must first set the deviceID field to the

hostname value that the switch acquires after–not before–you use the cns config initial global configuration command at the switch. Otherwise, subsequent cns config partial global configuration command operations malfunction.

Using Hostname, DeviceID, and ConfigID

In standalone mode, when a hostname value is set for a switch, the configuration server uses the hostname as the deviceID when an event is sent on hostname. If the hostname has not been set, the event is sent on the cn=<value> of the device.

In server mode, the hostname is not used. In this mode, the unique deviceID attribute is always used for sending an event on the bus. If this attribute is not set, you cannot update the switch.

These and other associated attributes (tag value pairs) are set when you run Setup on the Configuration Registrar.

4-4

Note For more information about running the setup program on the Configuration Registrar, see the Cisco

Intelligence Engine 2100 Series Configuration Registrar Manual.

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Understanding CNS Embedded Agents

The CNS event agent feature allows the switch to publish and subscribe to events on the event bus and works with the CNS configuration agent. The CNS configuration agent feature supports the switch by providing these features:

• Initial Configuration, page 4-5

• Incremental (Partial) Configuration, page 4-6

• Synchronized Configuration, page 4-6

Initial Configuration

When the switch first comes up, it attempts to get an IP address by broadcasting a DHCP request on the network. Assuming there is no DHCP server on the subnet, the distribution switch acts as a DHCP relay agent and forwards the request to the DHCP server. Upon receiving the request, the DHCP server assigns an IP address to the new switch and includes the TFTP server IP address, the path to the bootstrap configuration file, and the default gateway IP address in a unicast reply to the DHCP relay agent. The DHCP relay agent forwards the reply to the switch.

Understanding CNS Embedded Agents

The switch automatically configures the assigned IP address on interface VLAN 1 (the default) and downloads the bootstrap configuration file from the TFTP server. Upon successful download of the bootstrap configuration file, the switch loads the file in its running configuration.

The embedded CNS agents initiate communication with the IE2100 Configuration Registrar by using the appropriate configID and eventID. The Configuration Registrar maps the configID to a template and downloads the full configuration file to the switch.

Figure 4-2 shows a sample network configuration for retrieving the initial bootstrap configuration file

by using DHCP-based autoconfiguration.

Figure 4-2 Initial Configuration Overview

TFTP

IE2100

Configuration

Registrar

Access layer

WAN

DHCP relay agent default gatewayDistribution layer

switches

server

DHCP server

71445

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Configuring CNS Embedded Agents

Incremental (Partial) Configuration

After the network is running, new services can be added by using the CNS configuration agent. Incremental (partial) configurations can be sent to the switch. The actual configuration can be sent as an event payload by way of the event gateway (push operation) or as a signal event that triggers the switch to initiate a pull operation.

The switch can check the syntax of the configuration before applying it. If the syntax is correct, the switch applies the incremental configuration and publishes an event that signals success to the configuration server. If the switch does not apply the incremental configuration, it publishes an event showing an error status. When the switch has applied the incremental configuration, it can write it to NVRAM or wait until signaled to do so.

Synchronized Configuration

When the switch receives a configuration, it can defer application of the configuration upon receipt of a write-signal event. The write-signal event tells the switch not to save the updated configuration into its NVRAM. The switch uses the updated configuration as its running configuration. This ensures that the switch configuration is synchronized with other network activities before saving the configuration in NVRAM for use at the next reboot.

Chapter 4 Configuring IE2100 CNS Agents

Configuring CNS Embedded Agents

The CNS agents embedded in the switch Cisco IOS software allow the switch to be connected and automatically configured as described in the “Enabling Automated CNS Configuration” section on

page 4-6. If you want to change the configuration or install a custom configuration, see these sections

for instructions:

• Enabling the CNS Event Agent, page 4-8

• Enabling the CNS Configuration Agent, page 4-9

Enabling Automated CNS Configuration

To enable automated CNS configuration of the switch, you must first complete the prerequisites in

Table 4-1 . When you complete them, power on the switch. At the setup prompt, do nothing: The switch

begins the initial configuration as described in the “Initial Configuration” section on page 4-5. When the full configuration file is loaded on your switch, you need to do nothing else.

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Chapter 4 Configuring IE2100 CNS Agents

Table 4-1 Prerequisites for Enabling Automatic Configuration

Device Required Configuration

Access switch Factory default (no configuration file)

Distribution switch

DHCP server

TFTP server

IE2100 Configuration Registrar Create one or more templates for each type of device, and map the

Configuring CNS Embedded Agents

• IP helper address

• Enable DHCP relay agent

• IP routing (if used as default gateway)

• IP address assignment

• TFTP server IP address

• Path to bootstrap configuration file on the TFTP server

• Default gateway IP address

• Create a bootstrap configuration file that includes the CNS

configuration commands that enable the switch to communicate with the IE2100 Configuration Registrar.

• Configure the switch to use either the switch MAC address or

the serial number (instead of the default hostname) to generate the configID and eventID.

• Configure the CNS event agent to push the configuration file

to the switch.

configID of the device to the template.

Note For more information about running the setup program and creating templates on the Configuration

Registrar, see the Cisco Intelligence Engine 2100 Series Configuration Registrar Manual.

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Configuring CNS Embedded Agents

Enabling the CNS Event Agent

Note You must enable the CNS event agent on the switch before you enable the CNS configuration agent.

Beginning in privileged EXEC mode, follow these steps to enable the CNS event agent on the switch:

Command Purpose

Step 1

Step 2

configure terminal Enter global configuration mode.

cns event {ip-address | hostname} [port-number] [backup]

[init-retry retry-count] [keepalive seconds retry-count] [source ip-address]

Chapter 4 Configuring IE2100 CNS Agents

Enable the event agent, and enter the gateway parameters.

• For {ip-address | hostname}, enter either the

IP address or the hostname of the event gateway.

• (Optional) For port number, enter the port

number for the event gateway. The default port number is 11011.

Step 3

Step 4

Step 5

Step 6

• (Optional) Enter backup to show that this is the

backup gateway. (If omitted, this is the primary gateway.)

• (Optional) For init-retry retry-count, enter the

number of initial retries before switching to backup. The default is 3.

• (Optional) For keepalive seconds, enter how

often the switch sends keepalive messages. For retry-count, enter the number of unanswered keepalive messages that the switch sends before the connection is terminated. The default for each is 0.

• (Optional) For source ip-address, enter the

source IP address of this device.

Note Though visible in the command-line help

string, the encrypt and force-fmt1 keywords are not supported.

end Return to privileged EXEC mode.

show cns event connections Verify information about the event agent.

show running-config Verify your entries.

copy running-config startup-config (Optional) Save your entries in the configuration

file.

4-8

To disable the CNS event agent, use the no cns event {ip-address | hostname} global configuration command.

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This example shows how to enable the CNS event agent, set the IP address gateway to 10.180.1.27, set 120 seconds as the keepalive interval, and set 10 as the retry count.

Switch(config)# cns event 10.180.1.27 keepalive 120 10

Enabling the CNS Configuration Agent

After enabling the CNS event agent, start the CNS configuration agent on the switch. You can enable the configuration agent with these commands:

• the cns config initial global configuration command enables the configuration agent and initiates

an initial configuration on the switch.

• the cns config partial global configuration command enables the configuration agent and initiates

a partial configuration on the switch. You can then remotely send incremental configurations to the switch from the Configuration Registrar.

Enabling an Initial Configuration

Beginning in privileged EXEC mode, follow these steps to enable the CNS configuration agent and initiate an initial configuration on the switch:

Configuring CNS Embedded Agents

Step 1

Step 2

Command Purpose

configure terminal Enter global configuration mode.

cns config connect-intf interface-prefix [ping-interval

seconds] [retries num]

Enter the connect-interface-config submode, and specify the interface for connecting to the Configuration Registrar.

• Enter the interface-prefix for the connecting

interface. You must specify the interface type but need not specify the interface number.

• (Optional) For ping-interval seconds, enter the

interval between successive ping attempts. The range is 1 to 30 seconds. The default is 10 seconds.

• (Optional) For retries num, enter the number of

ping retries. The range is 1 to 30. The default is 5.

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Configuring CNS Embedded Agents

Command Purpose

Step 3

config-cli

line-cli

Step 4

Step 5

Step 6

Step 7

exit Return to global configuration mode.

hostname name Enter the hostname for the switch.

ip route network-number Establish a static route to the Configuration Registrar

cns id interface num {dns-reverse | ipaddress | mac-address} [event]

or cns id {hardware-serial | hostname | string string} [event]

Chapter 4 Configuring IE2100 CNS Agents

Enter config-cli to connect to the Configuration Registrar through the interface defined in cns config connect-intf. Enter line-cli to connect to the Registrar through modem dialup lines.

Note The config-cli interface configuration

command accepts the special directive character & that acts as a placeholder for the interface name. When the configuration is applied, the & is replaced with the interface name. For example, to connect through FastEthernet0/0, the command

ip route 0.0.0.0 0.0.0.0 &

command

FastEthernet0/0

ip route 0.0.0.0 0.0.0.0

whose IP address is network-number.

Set the unique eventID or configID used by the Configuration Registrar.

• For interface num, enter the type of

interface–for example, Ethernet, Group-Async, Loopback, or Virtual-Template. This setting specifies from which interface the IP or MAC address should be retrieved to define the unique ID.

• For {dns-reverse | ipaddress | mac-address}

enter dns-reverse to retrieve the hostname and assign it as the unique ID, enter ipaddress to use the IP address, or enter mac-address to use the MAC address as the unique ID.

config-cli

generates the

4-10

• (Optional) Enter event to set the ID to be the

event-id value used to identify the switch.

• For {hardware-serial | hostname|

string string}, enter hardware-serial to set the

switch serial number as the unique ID, enter hostname (the default) to select the switch hostname as the unique ID, or enter an arbitrary text string for string string as the unique ID.

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Chapter 4 Configuring IE2100 CNS Agents

Command Purpose

Step 8

cns config initial {ip-address | hostname} [port-number] [event] [no-persist] [page page] [source ip-address] [syntax-check]

Configuring CNS Embedded Agents

Enable the configuration agent, and initiate an initial configuration.

• For {ip-address | hostname}, enter the

IP address or the hostname of the configuration server.

• (Optional) For port-number, enter the port

number of the configuration server. The default port number is 80.

• (Optional) Enable event for configuration

success, failure, or warning messages when the configuration is finished.

• (Optional) Enable no-persist to suppress the

automatic writing to NVRAM of the configuration pulled as a result of entering the cns config initial global configuration command. If the no-persist keyword is not entered, using the cns config initial command causes the resultant configuration to be automatically written to NVRAM.

Step 9

Step 10

Step 11

• (Optional) For page page, enter the web page of

the initial configuration. The default is /Config/config/asp.

• (Optional) Enter source ip-address to use for

source IP address.

• (Optional) Enable syntax-check to check the

syntax when this parameter is entered.

Note Though visible in the command-line help

string, the encrypt keyword is not supported.

end Return to privileged EXEC mode.

show cns config connections Verify information about the configuration agent.

show running-config Verify your entries.

To disable the CNS configuration agent, use the no cns config initial {ip-address | hostname} global configuration command.

This example shows how to configure an initial configuration on a remote switch. The switch hostname is the unique ID. The CNS Configuration Registrar IP address is 172.28.129.22.

Switch(config)# cns config connect-intf serial ping-interval 1 retries 1 Switch(config-cns-conn-if)# config-cli ip address negotiated Switch(config-cns-conn-if)# config-cli encapsulation ppp Switch(config-cns-conn-if)# config-cli ip directed-broadcast Switch(config-cns-conn-if)# config-cli no keepalive Switch(config-cns-conn-if)# config-cli no shutdown Switch(config-cns-conn-if)# exit Switch(config)# hostname RemoteSwitch RemoteSwitch(config)# ip route 10.1.1.1 255.255.255.255 11.11.11.1 RemoteSwitch(config)# cns id Ethernet 0 ipaddress RemoteSwitch(config)# cns config initial 10.1.1.1 no-persist

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Configuring CNS Embedded Agents

Enabling a Partial Configuration

Beginning in privileged EXEC mode, follow these steps to enable the CNS configuration agent and to initiate a partial configuration on the switch:

Command Purpose

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

configure terminal Enter global configuration mode.

cns config partial {ip-address | hostname} [port-number] [source ip-address]

end Return to privileged EXEC mode.

show cns config stats

show cns config outstanding

show running-config Verify your entries.

copy running-config startup-config (Optional) Save your entries in the configuration

Chapter 4 Configuring IE2100 CNS Agents

Enable the configuration agent, and initiate a partial configuration.

• For {ip-address | hostname}, enter the

IP address or the hostname of the configuration server.

• (Optional) For port-number, enter the port

number of the configuration server. The default port number is 80.

• (Optional) Enter source ip-address to use for the

source IP address.

Note Though visible in the command-line help

string, the encrypt keyword is not supported.

Verify information about the configuration agent.

file.

4-12

To disable the CNS configuration agent, use the no cns config partial {ip-address | hostname} global configuration command. To cancel a partial configuration, use the cns config cancel privileged EXEC command.

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Chapter 4 Configuring IE2100 CNS Agents

Displaying CNS Configuration

You can use the privileged EXEC commands in Ta ble 4- 2 to display CNS Configuration information.

Table 4-2 Displaying CNS Configuration

Command Purpose

show cns config connections Displays the status of the CNS configuration agent connections.

show cns config outstanding Displays information about incremental (partial) CNS

configurations that have started but are not yet completed.

show cns config stats Displays statistics about the CNS configuration agent.

show cns event connections Displays the status of the CNS event agent connections.

show cns event stats Displays statistics about the CNS event agent.

show cns event subject Displays a list of event agent subjects that are subscribed to by

applications.

Displaying CNS Configuration

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Displaying CNS Configuration

Chapter 4 Configuring IE2100 CNS Agents

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CHAPTER

Clustering Switches

This chapter provides an overview of the concepts and of the procedures used to create and manage Catalyst 2960 switch clusters.

You can create and manage switch clusters by using Network Assistant, the command-line interface (CLI), or SNMP. Configuring switch clusters is more easily done from Network Assistant than through the CLI or SNMP. For getting started procedures about using Network Assistant to configure switch clusters, see Getting Started with Cisco Network Assistant, available on Cisco.com. For complete procedures about managing switch clusters, see the switch online help. For the CLI cluster commands, see the switch command reference.This chapter consists of these sections:

• Understanding Switch Clusters, page 5-1

• Using the CLI to Manage Switch Clusters, page 5-3

• Using SNMP to Manage Switch Clusters, page 5-4

Note We do not recommend using the ip http access-class global configuration command to limit access to

specific hosts or networks. Control access through the cluster command switch or by applying access control lists (ACLs) on interfaces that are configured with an IP address. For more information on ACLs, see Chapter 28, “Configuring Network Security with ACLs.”

Understanding Switch Clusters

These sections contain this information:

• Clustering Overview, page 5-1

• Cluster Command Switch Characteristics, page 5-2

• Standby Cluster Command Switch Characteristics, page 5-2

• Candidate Switch and Cluster Member Switch Characteristics, page 5-3

Clustering Overview

A switch cluster is a set of up to 16 connected, cluster-capable Catalyst switches that are managed as a single entity. The switches in the cluster use the switch clustering technology so that you can configure and troubleshoot a group of different Catalyst desktop switch platforms through a single IP address.

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Understanding Switch Clusters

Using switch clusters simplifies the management of multiple switches, regardless of their physical location and platform families. Clustering also provides redundancy through standby cluster command switches.

In a switch cluster, 1 switch must be the cluster command switch and up to 15 other switches can be cluster member switches. The total number of switches in a cluster cannot exceed 16 switches. The cluster command switch is the single point of access used to configure, manage, and monitor the cluster member switches. Cluster members can belong to only one cluster at a time.

Note If you configure Secure Socket Layer (SSL) Version 3.0 for a secure (HTTPS) connection, the SSL

connection stops at the command switch. Cluster member switches must run nonsecure HTTP. For more information about SSL, see the “Configuring the Switch for Secure Socket Layer HTTP” section on

page 8-37.

For more information about switch clustering, including cluster-planning considerations, see Getting Started with Cisco Network Assistant, available on Cisco.com. For a list of Catalyst switches eligible for switch clustering, including which ones can be cluster command switches and which ones can only be cluster member switches, and the required software versions, see the Release Notes for Cisco Network Assistant, available on Cisco.com.

Chapter 5 Clustering Switches

Cluster Command Switch Characteristics

A cluster command switch must meet these requirements:

• It is running Cisco IOS Release 12.2(25)FX or later.

• It has an IP address.

• It has Cisco Discovery Protocol (CDP) Version 2 enabled (the default).

• It is not a command or cluster member switch of another cluster.

• It is connected to the standby cluster command switches through the management VLAN and to the

cluster member switches through a common VLAN.

Note If your switch cluster has a Catalyst 2960 switch, it should be the cluster command switch unless the

cluster has a Catalyst 3750 switch or switch stack. If the switch cluster has a Catalyst 3750 switch or switch stack, that switch or switch stack should be the cluster command switch.

Standby Cluster Command Switch Characteristics

A standby cluster command switch must meet these requirements:

• It is running Cisco IOS Release 12.2(25)FX or later.

• It has an IP address.

5-2

• It has CDP Version 2 enabled.

• It is connected to the command switch and to other standby command switches through its

management VLAN.

• It is connected to all other cluster member switches (except the cluster command and standby

command switches) through a common VLAN.

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Chapter 5 Clustering Switches

Using the CLI to Manage Switch Clusters

• It is redundantly connected to the cluster so that connectivity to cluster member switches is

maintained.

• It is not a command or member switch of another cluster.

Note Standby cluster command switches must be the same type of switches as the cluster command

switch. For example, if the cluster command switch is a Catalyst 2960 switch, the standby cluster command switches must also be Catalyst 2960 switches. See the switch configuration guides of other cluster-capable switches for their requirements on standby cluster command switches.

Candidate Switch and Cluster Member Switch Characteristics

Candidate switches are cluster-capable switches that have not yet been added to a cluster. Cluster member switches are switches that have actually been added to a switch cluster. Although not required, a candidate or cluster member switch can have its own IP address and password.

To join a cluster, a candidate switch must meet these requirements:

• It is running cluster-capable software.

• It has CDP Version 2 enabled.

• It is not a command or cluster member switch of another cluster.

• If a cluster standby group exists, it is connected to every standby cluster command switch through

at least one common VLAN. The VLAN to each standby cluster command switch can be different.

• It is connected to the cluster command switch through at least one common VLAN.

Note Catalyst 1900, Catalyst 2820, Catalyst 2900 XL, Catalyst 2950, and Catalyst 3500 XL

candidate and cluster member switches must be connected through their management VLAN to the cluster command switch and standby cluster command switches. For complete information about these switches in a switch-cluster environment, see the software configuration guide for that specific switch.

This requirement does not apply if you have a Catalyst 2970, 2960, 3550, 3560, or 3750 cluster command switch. Candidate and cluster member switches can connect through any VLAN in common with the cluster command switch.

Using the CLI to Manage Switch Clusters

You can configure cluster member switches from the CLI by first logging into the cluster command switch. Enter the rcommand user EXEC command and the cluster member switch number to start a Telnet session (through a console or Telnet connection) and to access the cluster member switch CLI. The command mode changes, and the Cisco IOS commands operate as usual. Enter the exit privileged EXEC command on the cluster member switch to return to the command-switch CLI.

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This example shows how to log into member-switch 3 from the command-switch CLI:

switch# rcommand 3

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Using SNMP to Manage Switch Clusters

If you do not know the member-switch number, enter the show cluster members privileged EXEC command on the cluster command switch. For more information about the rcommand command and all other cluster commands, see the switch command reference.

The Telnet session accesses the member-switch CLI at the same privilege level as on the cluster command switch. The Cisco IOS commands then operate as usual. For instructions on configuring the switch for a Telnet session, see the “Disabling Password Recovery” section on page 8-5.

Catalyst 1900 and Catalyst 2820 CLI Considerations

If your switch cluster has Catalyst 1900 and Catalyst 2820 switches running standard edition software, the Telnet session accesses the management console (a menu-driven interface) if the cluster command switch is at privilege level 15. If the cluster command switch is at privilege level 1 to 14, you are prompted for the password to access the menu console.

Note Catalyst 1900, 2900 XL (4 MB), and 2820 switches are not supported in Network Assistant. The

switches appear as unknown devices in the Network Assistant Front Panel and Topology views.

Chapter 5 Clustering Switches

Command-switch privilege levels map to the Catalyst 1900 and Catalyst 2820 cluster member switches running standard and Enterprise Edition Software as follows:

• If the command-switch privilege level is 1 to 14, the cluster member switch is accessed at privilege

level 1.

• If the command-switch privilege level is 15, the cluster member switch is accessed at privilege

level 15.

Note The Catalyst 1900 and Catalyst 2820 CLI is available only on switches running Enterprise

Edition Software.

For more information about the Catalyst 1900 and Catalyst 2820 switches, see the installation and configuration guides for those switches.

Using SNMP to Manage Switch Clusters

When you first power on the switch, SNMP is enabled if you enter the IP information by using the setup program and accept its proposed configuration. If you did not use the setup program to enter the IP information and SNMP was not enabled, you can enable it as described in the “Configuring SNMP”

section on page 27-6. On Catalyst 1900 and Catalyst 2820 switches, SNMP is enabled by default.

When you create a cluster, the cluster command switch manages the exchange of messages between cluster member switches and an SNMP application. The cluster software on the cluster command switch appends the cluster member switch number (@esN, where N is the switch number) to the first configured read-write and read-only community strings on the cluster command switch and propagates them to the cluster member switch. The cluster command switch uses this community string to control the forwarding of gets, sets, and get-next messages between the SNMP management station and the cluster member switches.

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Chapter 5 Clustering Switches

Note When a cluster standby group is configured, the cluster command switch can change without your

knowledge. Use the first read-write and read-only community strings to communicate with the cluster command switch if there is a cluster standby group configured for the cluster.

If the cluster member switch does not have an IP address, the cluster command switch redirects traps from the cluster member switch to the management station, as shown in Figure 5-1. If a cluster member switch has its own IP address and community strings, the cluster member switch can send traps directly to the management station, without going through the cluster command switch.

If a cluster member switch has its own IP address and community strings, they can be used in addition to the access provided by the cluster command switch. For more information about SNMP and community strings, see Chapter 27, “Configuring SNMP.”

Figure 5-1 SNMP Management for a Cluster

Using SNMP to Manage Switch Clusters

SNMP Manager

Member 1 Member 2 Member 3

Trap 1, Trap 2, Trap 3

Tr ap

Command switch

Tr ap

33020

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Using SNMP to Manage Switch Clusters

Chapter 5 Clustering Switches

5-6

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Administering the Switch

This chapter describes how to perform one-time operations to administer the Catalyst 2960 switch.

This chapter consists of these sections:

• Managing the System Time and Date, page 6-1

• Configuring a System Name and Prompt, page 6-14

• Creating a Banner, page 6-17

• Managing the MAC Address Table, page 6-19

• Managing the ARP Table, page 6-26

Managing the System Time and Date

You can manage the system time and date on your switch using automatic configuration, such as the Network Time Protocol (NTP), or manual configuration methods.

CHAPTER

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Note For complete syntax and usage information for the commands used in this section, see the Cisco IOS

Configuration Fundamentals Command Reference, Release 12.2.

These sections contain this configuration information:

• Understanding the System Clock, page 6-2

• Understanding Network Time Protocol, page 6-2

• Configuring NTP, page 6-4

• Configuring Time and Date Manually, page 6-11

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Managing the System Time and Date

Understanding the System Clock

The heart of the time service is the system clock. This clock runs from the moment the system starts up and keeps track of the date and time.

The system clock can then be set from these sources:

• NTP

• Manual configuration

The system clock can provide time to these services:

• User show commands

• Logging and debugging messages

The system clock keeps track of time internally based on Universal Time Coordinated (UTC), also known as Greenwich Mean Time (GMT). You can configure information about the local time zone and summer time (daylight saving time) so that the time appears correctly for the local time zone.

The system clock keeps track of whether the time is authoritative or not (that is, whether it has been set by a time source considered to be authoritative). If it is not authoritative, the time is available only for display purposes and is not redistributed. For configuration information, see the “Configuring Time and

Date Manually” section on page 6-11.

Chapter 6 Administering the Switch

Understanding Network Time Protocol

The NTP is designed to time-synchronize a network of devices. NTP runs over User Datagram Protocol (UDP), which runs over IP. NTP is documented in RFC 1305.

An NTP network usually gets its time from an authoritative time source, such as a radio clock or an atomic clock attached to a time server. NTP then distributes this time across the network. NTP is extremely efficient; no more than one packet per minute is necessary to synchronize two devices to within a millisecond of one another.

NTP uses the concept of a stratum to describe how many NTP hops away a device is from an authoritative time source. A stratum 1 time server has a radio or atomic clock directly attached, a stratum 2 time server receives its time through NTP from a stratum 1 time server, and so on. A device running NTP automatically chooses as its time source the device with the lowest stratum number with which it communicates through NTP. This strategy effectively builds a self-organizing tree of NTP speakers.

NTP avoids synchronizing to a device whose time might not be accurate by never synchronizing to a device that is not synchronized. NTP also compares the time reported by several devices and does not synchronize to a device whose time is significantly different than the others, even if its stratum is lower.

The communications between devices running NTP (known as associations) are usually statically configured; each device is given the IP address of all devices with which it should form associations. Accurate timekeeping is possible by exchanging NTP messages between each pair of devices with an association. However, in a LAN environment, NTP can be configured to use IP broadcast messages instead. This alternative reduces configuration complexity because each device can simply be configured to send or receive broadcast messages. However, in that case, information flow is one-way only.

6-2

The time kept on a device is a critical resource; you should use the security features of NTP to avoid the accidental or malicious setting of an incorrect time. Two mechanisms are available: an access list-based restriction scheme and an encrypted authentication mechanism.

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Cisco Systems Cat2960-Xr User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

CONTENTS

Audience

Purpose

Preface

Conventions

Related Publications

Obtaining Documentation

Cisco.com

Documentation Feedback

Product Documentation DVD

Ordering Documentation

Cisco Product Security Overview

Reporting Security Problems in Cisco Products

Obtaining Technical Assistance

Cisco Technical Support & Documentation Website

Submitting a Service Request

Definitions of Service Request Severity

Obtaining Additional Publications and Information

Features

Overview

Performance Features

Management Options

Manageability Features

Availability Features

VLAN Features

Security Features

QoS and CoS Features

Default Settings After Initial Switch Configuration

Monitoring Features

Network Configuration Examples

Design Concepts for Using the Switch

Small to Medium-Sized Network Using Catalyst 2960 Switches

Long-Distance, High-Bandwidth Transport Configuration

Where to Go Next

Using the Command-Line Interface

Understanding Command Modes

Understanding the Help System

Understanding Abbreviated Commands

Understanding no and default Forms of Commands

Understanding CLI Error Messages

Using Command History

Changing the Command History Buffer Size

Using Editing Features

Recalling Commands

Disabling the Command History Feature

Enabling and Disabling Editing Features

Editing Commands through Keystrokes

Editing Command Lines that Wrap

Searching and Filtering Output of show and more Commands

Accessing the CLI

Accessing the CLI through a Console Connection or through Telnet

Assigning the Switch IP Address and Default Gateway

Understanding the Boot Process

Assigning Switch Information

Default Switch Information

Understanding DHCP-Based Autoconfiguration

DHCP Client Request Process

Configuring DHCP-Based Autoconfiguration

DHCP Server Configuration Guidelines

Configuring the TFTP Server

Configuring the DNS

Configuring the Relay Device

Obtaining Configuration Files

Example Configuration

Manually Assigning IP Information

Checking and Saving the Running Configuration

Modifying the Startup Configuration

Default Boot Configuration

Automatically Downloading a Configuration File

Specifying the Filename to Read and Write the System Configuration

Booting Manually

Booting a Specific Software Image

Controlling Environment Variables

Scheduling a Reload of the Software Image

Configuring a Scheduled Reload

Displaying Scheduled Reload Information