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Catalyst 2950 and Catalyst 2955 Switch
Software Configuration Guide
Cisco IOS Release 12.1(20)EA2
May 2004
Customer Order Number: DOC-7811380=
Text Part Number: 78-11380-10
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Catalyst 2950 and Catalyst 295 5 Swit ch Software Configuration Gui de
Copyright © 2001–2004 Cisco Sy stems , Inc. Al l rights r eserved 4
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CONTENTS
Preface xxix
Audience xxix
Purpose xxix
Conventions xxx
Related Publications xxxi
Obtaining Documentation xxxi
Cisco.com xxxi
Ordering Documentation xxxii
Documentation Feedback xxxii
Obtaining Technical Assistance xxxii
Cisco Technical S upport Website xxxiii
Submitting a Service Request xxxiii
Definitions of Service Request Severity xxxiii
Obtaining Additional Publications and Information xxxiv
CHAPTER
1 Overview 1-1
Features 1-1
Management Options 1-8
Management Interf ace Options 1-8
Advantage s of Us in g CMS and Cluster ing Switches 1-9
Network Configuration Examples 1-10
Design Concepts for Using the Switch 1-10
Small to Medium-Sized Network Configuration 1-13
Collapsed Backbone and Switch Cluster Configuration 1-14
Hotel Network Confi guration 1-15
Service-Provider Central-Office Configuration 1-18
Large Campus Configuration 1-19
Multidwelling Network Using Catalyst 2950 Switches 1-20
Long-Distance, High-Bandwidth Transport Configuration 1-22
Where to Go Next 1-22
Contents
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CHAPTER
2 Using the Command-Line Interface 2-1
Cisco IOS Command Modes 2-1
Getting Help 2-3
Abbreviating Commands 2-4
Using no and default Forms of Commands 2-4
Understanding CLI Messages 2-5
Using Command History 2-5
Changing the Command Hi story Buffer Size 2-5
Recalling Commands 2-6
Disabling the Command History Feature 2-6
Using Editing Features 2-6
Enabling and Disa bling Editing Features 2-6
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 from a Browser 2-10
CHAPTER
3 Configuring Catalyst 2955 Switch Alarms 3-1
Understanding Catalyst 2955 Switch Alarms 3-1
Global Status Monitoring Alarms 3-2
FCS Error Hysteres is Threshold 3-2
Port Status Monitoring Alarms 3-3
Triggering Alarm Options 3-3
Configuring Catalyst 2955 Switch Alarms 3-4
Default Catalyst2955 Switch Alarm Configura tion 3-4
Configuring the Power Supply Alarm 3-5
Setting the Power Mode 3-5
Setting the Power Su pply Alarm Options 3-5
Configuring th e Switch Temperature Alarms 3-6
Setting a Secondary Temperature Threshold for the Swi tch 3-6
Associatin g th e Te m p er ature Alarms to a R ela y 3-7
Configuring the FCS Bit Error Rate Alarm 3-7
Setting the FCS Err or Threshold 3-8
Setting the FCS Error Hysteresis Threshold 3-8
Contents
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Configuring Alarm Profiles 3-9
Creating or Modifyi ng an Alarm Profile 3-9
Attaching an Alarm Profile to a Specific Port 3-10
Enabling SNMP Traps 3-11
Displaying Cata lyst 2955 Switch Alarms Statu s 3-11
CHAPTER
4 Getting Started with CMS 4-1
Understanding CMS 4-1
Front Panel View 4-1
Topology View 4-2
CMS Menu Bar, Toolbar, and Fe ature Bar 4-2
Online Help 4-5
Configuration Modes 4-5
Guide Mode 4-5
Expert Mode 4-6
Wizards 4-6
Privilege Lev el s 4-7
Access to Olde r Sw itches in a Cluste r 4-7
Configuring CMS 4-7
CMS Requirements 4-8
Minimum Hardware Configurati on 4-8
Operating System and Browser Support 4-8
CMS Plug-In 4-9
Cross-Platform Considerations 4-9
HTTP Access to CMS 4-9
Specifying an HTTP Port (Nondefault Configuration Only) 4-10
Configuring an Authentication Method (Nondefault Configuration Only) 4-10
Displaying CMS 4-10
Launching CMS 4-10
Front Panel View 4-13
Topology View 4-14
CMS Icons 4-15
Where to Go Next 4-15
Contents
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CHAPTER
5 Assigning the Switch IP Address and Default Gateway 5-1
Understanding the Boot Process 5-1
Assigning Switch Information 5-2
Default Switch Information 5-3
Understanding DHCP-Based Autoconfiguration 5-3
DHCP Client Request Process 5-4
Configuring DHCP-Based Autoconfiguration 5-5
DHCP Server Configuration Guidelines 5-5
Configuring the TFTP Server 5-6
Configuring the DNS 5-7
Configuring the Relay Device 5-7
Obtaining Configuration Files 5-8
Example Configuration 5-9
Manually Assigning IP Information 5-10
Checking and Saving the Running Configuration 5-11
Modifying the S ta rtup Configurat ion 5-11
Default Boot Configuration 5-12
Automatically Downloading a Configuration File 5-12
Specifying the Filename to Read and Write the System Configuration 5-12
Booting Manually 5-13
Booting a Specific Software Image 5-13
Controlling Environment Variables 5-14
Scheduling a Reload of the Software Image 5-16
Configuring a Scheduled Reload 5-16
Displaying Sched uled Reload Information 5-17
CHAPTER
6 Configuring IE2100 CNS Agents 6-1
Understanding IE2100 Series Configuration Registrar Software 6-1
CNS Configuration Service 6-2
CNS Event Service 6-3
NameSpace M a pper 6-3
What You Should Know About ConfigID, DeviceID, and Host Name 6-3
ConfigID 6-3
DeviceID 6-4
Host Name and DeviceID 6-4
Using Host Name, DeviceID, and ConfigID 6-4
Contents
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Understanding CNS Embedded Agents 6-5
Initial Configuration 6-5
Incremental (P ar tia l ) Co nf ig ur ation 6-6
Synchronized Configuration 6-6
Configuring CNS Embe dded Agents 6-6
Enabling Automate d CNS Configuration 6-6
Enabling the C NS Ev e nt Agent 6-8
Enabling the CNS Configuration Agent 6-9
Enabling an Initial Configuration 6-9
Enabling a Partial Configuration 6-12
Displaying CNS Configuration 6-13
CHAPTER
7 Clustering Switches 7-1
Understanding Switch Clusters 7-2
Command Switch Characteristics 7-3
Standby Command Switch Characteristics 7-3
Candidate Switch and Member Switch Characteristics 7-4
Planning a Sw itc h Cluster 7-5
Automatic Discove ry of Cluster Candidates and Members 7-5
Discovery th ro ug h CD P H op s 7-6
Discovery through Non-CDP-Capable and Noncluster-Capable Devices 7-7
Discovery through the Same Management VLAN 7-8
Discovery through Di fferent Management VLANs 7-9
Discovery of Newly Installed Switches 7-10
HSRP and Standby Command Switches 7-11
Virtual IP Addres s es 7-12
Other Considerations for Cluster Standby Groups 7-12
Automatic Recovery of Cluster Configuration 7-14
IP Addresses 7-14
Host Names 7-15
Passwords 7-15
SNMP Community Strings 7-15
TACACS+ and RADIUS 7-16
Access Modes in CMS 7-16
Management VLAN 7-16
LRE Profiles 7-17
Availability of Switch-Specific Features in Switch Clusters 7-17
Contents
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Creating a Switch Cluster 7-18
Enabling a Command Switch 7-18
Adding Member Switches 7-19
Creating a Cluster Standby Group 7-21
Verifying a Switch Cl uster 7-22
Using the CLI to Manage Switch Clusters 7-23
Catalyst1900 and Catalyst2820 CLI Considerations 7-24
Using SNMP to Manage Sw itch Clusters 7-24
CHAPTER
8 Administering the Switch 8-1
Managing the System Time and Date 8-1
Understanding the System Clock 8-1
Understanding Network Time Protocol 8-2
Configuring NTP 8-3
Default NTP Config uration 8-4
Configuring NTP Authentication 8-4
Configuring NTP Associations 8-6
Configuring NTP Broadcast Service 8-7
Configuring NTP Ac cess Restrictions 8-8
Configuring the Source IP Address for NTP Packets 8-10
Displaying the NTP C onfiguration 8-11
Configuring Ti me and Date Manually 8-11
Setting the System Clock 8-12
Displaying the Time and Date Configuration 8-12
Configuring the Time Zone 8-13
Configuring Summer Time (Daylight Saving Time) 8-14
Configuring a System Name and Prompt 8-16
Default System Name and Prompt Configuration 8-16
Configuring a System Name 8-16
Configuring a System Prompt 8-17
Understanding DNS 8-17
Default DNS Configuration 8-18
Setting Up DNS 8-18
Displaying the DNS Configuration 8-19
Creating a Banner 8-19
Default Banner Con figuration 8-19
Configuring a Message-of-the-Day Login Banner 8-20
Configuring a Login Banner 8-21
Contents
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Managing the MAC Address Table 8-21
Building the Address Table 8-22
MAC Addresses and VLANs 8-22
Default MAC Address Tab le Configuration 8-23
Changing the Addres s Aging Time 8-23
Removing Dynamic Address Entries 8-24
Configuring MAC Address Notification Traps 8-24
Adding and Removing Static Address Entries 8-26
Configuring Unicast MAC Address Filtering 8-27
Displaying Addre ss Table Entries 8-28
Managing the ARP Table 8-28
CHAPTER
9 Configuring Switch-Based Authentication 9-1
Preventing Unauthorized Access to Your Switch 9-1
Protecting Access to Privileged EXEC Commands 9-2
Default Password and Privilege Level Configuration 9-2
Setting or Changing a Static Enable Password 9-3
Protecting Enable and Enable Secret Passwords with Encryption 9-4
Disabling Password Recovery 9-5
Setting a Telnet Password for a Terminal Line 9-6
Configuring User name and Password Pairs 9-7
Configuring Multiple Privilege Levels 9-8
Setting the Priv ilege Level for a Command 9-8
Changing the Default Privilege Level for Lines 9-9
Logging into and Exiting a Privilege Level 9-10
Controlling Switch Access with TACACS+ 9-10
Understanding TACACS+ 9-10
TACACS+ Operation 9-12
Configuring TACACS+ 9-12
Default TACACS+ Confi guration 9-13
Identifying the TACACS+ Server Host and Setting th e Authentication Key 9-13
Configuring TACACS+ Login Authentication 9-14
Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 9-16
Starting TACACS+ Accounting 9-17
Displaying the TA CACS+ Configuration 9-17
Controlling Switch Access with RADIUS 9-18
Understanding RADIUS 9-18
RADIUS Operation 9-19
Contents
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Configuring RADIUS 9-20
Default RADIUS Configu ration 9-20
Identifying the RADIUS Server Host 9-21
Configuring RADI US Login Authentication 9-23
Defining AAA Server Groups 9-25
Configuring RADIUS Authorization for User Privileged Access and Network Services 9-27
Starting RADIUS Accounting 9-28
Configuring Set tings for All RADIUS Servers 9-29
Configuring the Switch to Use Vendor-Specific RADIUS Attributes 9-29
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 9-30
Displaying the RADIUS Configuration 9-31
Configuring the Switch for Local Authentication and Authorization 9-32
Configuring the Switch for Secure Shell 9-33
Understanding SSH 9-33
SSH Servers, Integrated Clients, and Supported Versions 9-33
Limitations 9-34
Configuring SSH 9-34
Configuration Guidelines 9-34
Cryptographic Software Image Guidelines 9-35
Setting Up the Switch to Run SSH 9-35
Configuring the SSH Server 9-36
Displaying the SS H C onfiguration and Status 9-37
CHAPTER
10 Configuring 802.1x Port-Based Authentication 10-1
Understanding 80 2.1x Port-Based Authentication 10-1
Device Roles 10-2
Authentication Initiation and Message Exchange 10-3
Ports in Authorized and Unauthorized States 10-4
802.1x Accounting 10-5
Supported Topologies 10-5
Using 802.1x with Port Security 10-6
Using 802.1x with Voice VLAN Ports 10-7
Using 802.1x with VLAN Assignment 10-7
Using 802.1x with Guest VLAN 10-8
Configuring 802.1x Authentication 10-9
Default 802.1x Configuration 10-9
802.1x Configuration Guidelines 10-10
Upgrading from a Previous Software Release 10-11
Enabling 802.1x Authentication 10-11
Contents
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Configuring th e Switch-to-RADIUS-Server Communic ation 10-13
Enabling Periodic Re-Authentication 10-14
Manually Re-Authenticating a Client Connected to a Port 10-15
Changing the Quiet Period 10-15
Changing the Switch-to-Client Retransmission Time 10-15
Setting the Switch-to-Client Frame-Retransmission Number 10-16
Configuring the Host Mode 10-17
Configuring a Guest VLAN 10-18
Resetting the 802.1x Configuration to the Default Values 10-18
Configuring 802.1x Authentication 10-19
Configuring 802.1x Accounting 10-20
Displaying 802.1x Statistics and Status 10-21
CHAPTER
11 Configuring Interface Characteristics 11-1
Understanding Interface Types 11-1
Access Ports 11-2
Trunk Ports 11-2
Port-Based VLANs 11-3
EtherChannel Por t Groups 11-3
Connecting Interfaces 11-4
Using the Interface Command 11-4
Procedures for Configuring Interfaces 11-5
Configuring a Range of Interfaces 11-5
Configuring and Using Interface-Range Macros 11-7
Configuring Ethernet Interfaces 11-8
Default Etherne t Interface Configuration 11-9
Configuring Interface Speed and Duplex Mode 11-10
Configuration Guidelines 11-10
Setting the Inte rface Speed and Duplex Parameters on a Non-LRE Switch Port 11-12
Setting the Interface Speed and Duplex Parameter s on an LRE Switch Port 11-12
Configuring Media Types for Gigabit Ethernet Interfaces on LRE Switches 11-13
Configuring IEEE 802.3z Flow Control on Giga bit Ethernet Ports 11-13
Adding a Description for an Interface 11-14
Monitoring and Maintaining the Interfaces 11-15
Monitoring Interface and Controller Status 11-15
Clearing and Reset ting Interfaces and Counters 11-16
Shutting Down and Restarting the Interface 11-17
Contents
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CHAPTER
12 Configuring Smartports Macros 12-1
Understanding Smartports Macros 12-1
Configuring Smar tports Macros 12-2
Default Smartports Macro Configuration 12-2
Smartports Macro Con figuration Guidelines 12-3
Creating Smartports Macros 12-4
Applying Smartports Macros 12-5
Applying Cisco-default Smartports Macros 12-6
Displaying Smartports Macros 12-8
CHAPTER
13 Configuring LRE 13-1
Understanding LRE Features 13-1
Ports on the Cat alyst 2950 LRE Sw itc h es 13-1
LRE Links and LRE Profiles 13-2
LRE Profiles 13-2
LRE Sequences 13-5
CPE Ethernet Links 13-6
LRE Link Monitor 13-7
LRE Message Logging Pr ocess 13-8
Configuring LRE Ports 13-8
Default LRE Confi guration 13-9
Environmental Guidelines for LRE Links 13-9
Guidelines for Us ing LRE Profiles 13-10
CPE Ethernet Link Guidelines 13-11
Guidelines for Co nfiguring Cisco 575 LRE CPEs and 5 76 LRE 997 CPEs 13-11
Guidelines for Co nfiguring Cisco 585 LRE CPEs 13-12
Assigning a Global Profile to All LRE Ports 13-12
Assigning a Profile to a Specific LRE Port 13-13
Assigning a Global Sequence to All LRE Ports 13-13
Assigning a Sequence to a Speci f ic LR E Po rt 13-14
Using Rate Selection to Automatically Assign Profiles 13-14
Precedence 13-15
Profile Lockin g 13-15
Link Qualification and SNR Margins 13-16
Configuring LRE Link Persistence 13-19
Configuring LRE Link Monitor 13-20
Configuring LRE Interleave 13-20
Configuring Upst ream Power Back-Off 13-21
Contents
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Configuring CPE Toggle 13-22
Configuring Syslog Export 13-22
Upgrading LRE Switch Firmware 13-23
Configuring for an LRE Upgrade 13-24
Performing an LRE Upgrade 13-24
Global Configuration of LRE Upgrades 13-25
Controller Configuration of LRE Upgrades 13-25
LRE Upgrade Details 13-26
LRE Upgrade Example 13-26
Displaying LRE Status 13-27
CHAPTER
14 Configuring STP 14-1
Understanding Spanning-Tree Features 14-1
STP Overview 14-2
Spanning-Tree To pology and BPDUs 14-3
Bridge ID, Switch Priority, and Extended System ID 14-4
Spanning-Tree I nterface States 14-4
Blocking State 14-6
Listening State 14-6
Learning State 14-6
Forwarding State 14-6
Disabled State 14-7
How a Switch or Port Becomes the Root Switch or Root Port 14-7
Spanning Tree and Redundant Connectivity 14-8
Spanning-Tree Add ress Management 14-8
Accelerated Aging to Retain Connectivity 14-8
Spanning-Tree Mode s and Protocols 14-9
Supported Spanning-Tree Instances 14-9
Spanning-Tree Interoperability and Backward Compatibility 14-10
STP and IEEE 802.1Q Tr unks 14-10
Configuring Spanning-Tree Features 14-11
Default Spanning -Tree Configuration 14-11
Spanning-Tree Configuration Guidelines 14-12
Changing the Spanning-Tree Mode 14-13
Disabling Spanning Tree 14-14
Configuring the Root Switch 14-14
Configuring a Secondary Root Switch 14-16
Configuring the Port Priority 14-17
Configuring the Path Cost 14-19
Contents
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Configuring the Switch Priority of a VLAN 14-20
Configuring Spanning-Tree Timers 14-21
Configuring the Hello Time 14-21
Configuring th e Forwarding-Delay Time for a VLAN 14-22
Configuring th e Maximum-Aging Time for a VLAN 14-22
Configuring Spanning Tree for Use in a Cascaded Stack 14-23
Displaying the Spanning-Tree Status 14-24
CHAPTER
15 Configuring MSTP 15-1
Understanding MSTP 15-2
Multiple Spanning-Tree Regions 15-2
IST, CIST, and CST 15-2
Operations Within an MST Region 15-3
Operations Betwee n MST Regions 15-3
Hop Count 15-4
Boundary Ports 15-5
Interoperability with 802.1D STP 15-5
Understanding RSTP 15-6
Port Roles and the Active Topology 15-6
Rapid Convergence 15-7
Synchronization of Port Roles 15-8
Bridge Protocol Data Unit Format and Processing 15-9
Processing Super ior BPDU Information 15-10
Processing Inferior BPDU Information 15-10
Topology Changes 15-10
Configuring MSTP Features 15-11
Default MSTP Config uration 15-12
MSTP Configuration Gui delines 15-12
Specifying the MST Region Configuration and Enabling MSTP 15-13
Configuring the Root Switch 15-14
Configuring a Sec ondary Root Switch 15-16
Configuring the Port Priority 15-17
Configuring the Path Cost 15-18
Configuring the Switch Priority 15-19
Configuring the Hello Time 15-19
Configuring th e Forwarding-Delay Time 15-20
Configuring th e Maximum-Aging Time 15-21
Configuring the Maximum-Hop Count 15-21
Contents
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Specifying the Link Type to Ensure Rapid Transitions 15-22
Restarting the Protocol Migration Process 15-22
Displaying the MST Configuration and Status 15-23
CHAPTER
16 Configuring Optional Spanning-Tree Features 16-1
Understanding Optional Spanning-Tree Features 16-1
Understanding Po rt Fast 16-2
Understanding BPD U Guard 16-2
Understanding BPDU Filtering 16-3
Understanding UplinkFast 16-3
Understanding Cross-Stack UplinkFast 16-5
How CSUF Works 16-5
Events that Cause Fast Convergence 16-7
Limitations 16-7
Connecting the Stack Ports 16-8
Understanding BackboneFast 16-9
Understanding EtherChannel Guard 16-11
Understanding Root Guard 16-11
Understanding Loop Guard 16-12
Configuring Optional Spanning-Tree Features 16-12
Default Optional Spanning-Tree Configuration 16-13
Optional Spanning-Tree Configuration Guidelines 16-13
Enabling Port Fast 16-13
Enabling BPDU Guard 16-14
Enabling BPDU Filtering 16-15
Enabling Uplink Fast for Use with Redundant Links 16-16
Enabling Cross-Stack UplinkFast 16-17
Enabling BackboneFast 16-18
Enabling EtherChannel Guard 16-18
Enabling Root Guard 16-19
Enabling Loop Guard 16-19
Displaying the Spanning-Tree Status 16-20
CHAPTER
17 Configuring VLANs 17-1
Understanding VLANs 17-1
Supported VLANs 17-2
VLAN Port Membership Modes 17-3
Contents
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Configuring Nor mal-Range VLANs 17-4
Token Ring VLANs 17-5
Normal-Range VLAN Configuration Guidelines 17-5
VLAN Configuration Mode Options 17-6
VLAN Configuration in config-vlan Mode 17-6
VLAN Configuration in VLAN Configuration Mode 17-6
Saving VLAN Configuration 17-7
Default Etherne t VLAN Configuration 17-7
Creating or Modifying an Ethernet VLAN 17-8
Deleting a VLAN 17-10
Assigning St at ic-Access Port s to a VLAN 17-11
Configuring Ext ended-Range VLANs 17-12
Default VLAN Configuration 17-12
Extended-Range VLAN Configuration Guidelines 17-12
Creating an Extended-Range VLAN 17-13
Displaying VLANs 17-14
Configuring VLAN Tr unks 17-15
Trunking Overview 17-15
802.1Q Configura tion Considerations 17-16
Default Layer 2 Ethernet Inte rfa c e VL A N Co nf ig uration 17-17
Configuring an Ethernet Interface as a Trunk Port 17-17
Interaction with Other Features 17-18
Configuring a Trunk Port 17-18
Defining the Allo w e d V LA N s on a Tr un k 17-19
Changing the Pruning-Eligible List 17-20
Configuring the Native VLAN for Untagged Traffic 17-21
Load Sharing Using STP 17-22
Load Sharing Using STP Port Priorities 17-22
Load Sharing Using STP Path Cost 17-24
Configuring VMPS 17-25
Understanding VMPS 17-25
Dynamic Port VLAN Membership 17-26
VMPS Databa se Co nfiguration Fi le 17-26
Default VMPS Client Configuration 17-27
VMPS Configu ra tion Guidelines 17-27
Contents
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Configuring the VMPS Client 17-28
Entering the IP Address of the VMPS 17-28
Configuring Dynamic Access Ports on VMPS Clients 17-28
Reconfirming VLAN Memberships 17-29
Changing the Reconfirmation Interval 17-29
Changing the Retry Count 17-30
Monitoring the VMPS 17-30
Troubleshooting Dynamic Port VLAN Membership 17-31
VMPS Configuration Example 17-31
CHAPTER
18 Configuring VTP 18-1
Understanding VTP 18-1
The VTP Domain 18-2
VTP Modes 18-3
VTP Advertisements 18-3
VTP Version 2 18-4
VTP Pruning 18-4
Configuring VTP 18-6
Default VTP Confi guration 18-6
VTP Configuration Options 18-7
VTP Configuration in Global Configuration Mode 18-7
VTP Configuration in VLAN Configuration Mode 18-7
VTP Configuration Guidelines 18-8
Domain Names 18-8
Passwords 18-8
Upgrading from Pr evious Softwa re Re le ases 18-8
VTP Version 18-9
Configuration Requirements 18-9
Configuring a VTP Server 18-9
Configuring a VTP Client 18-11
Disabling VTP (VTP Transparent Mode) 18-12
Enabling VTP Version 2 18-13
Enabling VTP Pruning 18-14
Adding a VTP Client Switch to a VTP Domain 18-14
Monitoring VTP 18-16
Contents
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CHAPTER
19 Configuring Voice VLAN 19-1
Understanding Voice VLAN 19-1
Configuring Voi ce VLAN 19-2
Default Voice VLAN Configuration 19-2
Voice VLAN Config uration Guidelines 19-3
Configuring a Port to Connect to a Cisco7960 IP Phone 19-3
Configuring Ports to Carry Voice Traffic in 802.1Q Frames 19-4
Configuring Ports to Carry Voice Traffic in 802.1p Priority-Tagged Frames 19-4
Overriding the CoS Priority of Incoming Data Frames 19-5
Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames 19-6
Displaying Voic e VLAN 19-6
CHAPTER
20 Configuring DHCP Features 20-1
Understanding DHCP Features 20-1
DHCP Server 20-2
DHCP Relay Agent 20-2
DHCP Snooping 20-2
Option-82 Data Insertion 20-3
Configuring DHCP Features 20-5
Default DHCP Config uration 20-5
DHCP Snooping Configuration Guidelines 20-6
Configuring the DHCP Server 20-6
Enabling DHCP Snoopi ng and Option 82 20-7
Displaying DHCP In formation 20-8
Displaying a Binding Table 20-8
Displaying the DHCP Snooping Configuration 20-8
CHAPTER
21 Configuring IGMP Snooping and MVR 21-1
Understanding IGMP Snooping 21-1
IGMP Versions 21-2
Joining a Multicast Group 21-3
Leaving a Multicast Group 21-4
Immediate-Leave Processing 21-5
IGMP Report Suppression 21-5
Source-Only Networks 21-5
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Configuring IGMP Snooping 21-6
Default IGMP Snoo ping Configuration 21-6
Enabling or Disabling IGMP Snooping 21-7
Setting the Snoopi ng Method 21-8
Configuring a Multicast Router Port 21-9
Configuring a Host Statically to Join a Group 21-10
Enabling IGMP Immedi ate-Leave Processing 21-10
Disabling IGMP Report Suppression 21-11
Disabling IP Multicast-Source-Only Learning 21-11
Configuring the Aging Time 21-12
Displaying IGMP Sno oping Information 21-13
Understanding Multicast VLAN Registration 21-14
Using MVR in a Multicast Television Application 21-15
Configuring MV R 21-17
Default MVR Configuration 21-17
MVR Configuration Guidelines and Limitations 21-17
Configuring MVR Global Parameters 21-18
Configuring MVR Interfaces 21-19
Displaying MVR Information 21-21
Configuring IG M P Fi lt ering and Throttling 21-21
Default IGMP Filtering and Throttling Configuration 21-22
Configuring IGMP Profiles 21-22
Applying IGMP Profil es 21-24
Setting the Maximum Number of IGMP Groups 21-25
Configuring the IGMP Throttling Action 21-25
Displaying IGMP Filtering and Throttling Configuration 21-27
CHAPTER
22 Configuring Port-Based Traffic Control 22-1
Configuring Sto rm Control 22-1
Understanding Storm Control 22-2
Default Storm Control Configuration 22-2
Enabling Storm Control 22-2
Disabling Storm Control 22-4
Configuring Protected Ports 22-4
Configuring Port Blocking 22-5
Blocking Flooded Traffic on an Interface 22-5
Resuming Normal Forwarding on a Port 22-6
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Configuring Port Security 22-7
Understanding Po rt Security 22-7
Secure MAC Addresses 22-7
Security Viol at ions 22-8
Default Port Security Configuration 22-9
Port Security Configuration Guidelines 22-9
Enabling and Configuring Port Security 22-10
Enabling and Confi guring Port Security Aging 22-12
Displaying Port -Based Traffic Control Setti ngs 22-13
CHAPTER
23 Configuring UDLD 23-1
Understanding UDLD 23-1
Modes of Operation 23-1
Methods to Detect Unidirectional Links 23-2
Configuring UDLD 23-4
Default UDLD Configuration 23-4
Configuratio n Guidelines 23-4
Enabling UDLD Globally 23-5
Enabling UDLD on an Interface 23-5
Resetting an Interf ace Shut Down by UDLD 23-6
Displaying UDLD Status 23-7
CHAPTER
24 Configuring CDP 24-1
Understanding CDP 24-1
Configuring CDP 24-2
Default CDP Config uration 24-2
Configuring the CDP Characteristics 24-2
Disabling and Enabling CDP 24-3
Disabling and Enabling CDP on an Interface 24-4
Monitoring and Maintaining CDP 24-5
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CHAPTER
25 Configuring SPAN and RSPAN 25-1
Understanding SPAN and RSPAN 25-1
SPAN and RSP A N Conc ep t s and Terminolog y 25-3
SPAN Session 25-3
Traffic Types 25-3
Source Port 25-4
Destination Por t 25-4
Reflector Port 25-5
SPAN Traffic 25-5
SPAN and RSPAN Interaction with Other Features 25-5
SPAN and RSPAN Session Limits 25-6
Default SPAN and RSPAN Configuration 25-7
Configuring SPAN 25-7
SPAN Configuration Guidelines 25-7
Creating a SPAN Session and Specifying Ports to Monitor 25-8
Creating a SPAN Session and Enabling Ingress Traffic 25-9
Removing Ports from a SPAN Se ss io n 25-11
Configuring RSPAN 25-12
RSPAN Configuration Guidelines 25-12
Configuring a VLAN as an RSPAN VLAN 25-13
Creating an RSPAN Source Session 25-13
Creating an RSPAN Destination Session 25-15
Removing Ports from an RSPAN Se s sion 25-16
Displaying SPAN and RSPAN Status 25-17
CHAPTER
26 Configuring RMON 26-1
Understanding RMON 26-1
Configuring RMON 26-2
Default RMON Configuration 26-3
Configuring RMON Alarms and Events 26-3
Configuring RMON Col lection on an Interface 26-5
Displaying RMON Status 26-6
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CHAPTER
27 Configuring System Message Logging 27-1
Understanding System Message Logging 27-1
Configuring System Message Logging 27-2
System Log Message Format 27-2
Default System Message Logging Configuration 27-3
Disabling and Enabling Message Logging 27-4
Setting the Message D isplay Destination Device 27-4
Synchronizing Log Messages 27-6
Enabling and Disabling Timestamps on Log Messages 27-7
Enabling and Disabling Sequence Numbers in Log Messages 27-8
Defining the Message Severity Level 27-8
Limiting Syslog Messages Sent to the History Table and to SNMP 27-10
Configuring UNIX Syslog Servers 27-11
Logging Messages to a UNIX Syslog Daemon 27-11
Configuring the UNIX System Logging Facility 27-11
Displaying the Lo gging Configuration 27-13
CHAPTER
28 Configuring SNMP 28-1
Understanding SNMP 28-1
SNMP Versions 28-2
SNMP Manager Functions 28-3
SNMP Agent Fu nc ti on s 28-4
SNMP Community Strings 28-4
Using SNMP to Access MIB Variables 28-4
SNMP Notifications 28-5
Configuring SNMP 28-5
Default SNMP Configuration 28-6
SNMP Configuration Guidelines 28-6
Disabling the SNMP Agent 28-7
Configuring Commun ity Strings 28-7
Configuring SNMP Gro ups and Users 28-9
Configuring SNMP Not ifications 28-11
Setting the Agent Co ntact and Location Information 28-14
Limiting TFTP Servers Used Through SNMP 28-14
SNMP Exampl es 28-15
Displaying SNMP Status 28-16
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CHAPTER
29 Configuring Network Security with ACLs 29-1
Understanding ACLs 29-2
Handling Fragmented and Unfragmented Traffic 29-3
Understanding Access Control Parameters 29-4
Guidelines for Applying ACLs to Physical Inte rfaces 29-5
Configuring ACLs 29-6
Unsupported Features 29-7
Creating Standard and Extended IP ACLs 29-7
ACL Numbers 29-8
Creating a Numbered Standard ACL 29-9
Creating a Numbered Extended ACL 29-10
Creating Named Standard and Extended ACLs 29-13
Applying Time Ranges to ACLs 29-15
Including Comments About Entries in ACLs 29-17
Creating Named MAC Extended ACLs 29-18
Creating MAC Access Groups 29-19
Applying ACLs to Ter m inal Lines or Physical Interf aces 29-19
Applying AC Ls to a Te rm i nal Line 29-20
Applying ACLs to a Physical Interface 29-20
Displaying ACL Information 29-21
Displaying ACLs 29-21
Displaying Access Groups 29-22
Examples for Compiling ACLs 29-23
Numbered ACL Examples 29-25
Extended ACL Examples 29-25
Named ACL Example 29-25
Commented IP AC L En tr y Exa m ples 29-25
CHAPTER
30 Configuring QoS 30-1
Understanding QoS 30-2
Basic QoS Model 30-4
Classification 30-5
Classification Based on QoS ACLs 30-5
Classification Based on Class Maps and Policy Maps 30-6
Policing and Marking 30-7
Mapping Tables 30-8
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Queueing and Scheduling 30-8
How Class of Service Works 30-8
Port Priority 30-8
Port Scheduling 30-8
Egress CoS Queues 30-9
Configuring Auto-QoS 30-9
Generated Auto-QoS Configuration 30-10
Effects of Auto-QoS on the Configuration 30-13
Configuratio n Guidelines 30-13
Upgrading from a Previous Software Release 30-14
Enabling Auto-QoS for VoIP 30-14
Displaying Auto- Q oS Information 30-15
Auto-QoS Configuration Example 30-16
Configuring Standard QoS 30-18
Default Standard QoS Configuration 30-18
Configuratio n Guidelines 30-19
Configuring Classification Using Port Trust States 30-20
Configuring the Trust State on Ports within the Q oS Domain 30-20
Configuring the CoS Value for an Interface 30-23
Configuring Trusted Boundary 30-23
Enabling Pass-Through Mode 30-25
Configuring a QoS Policy 30-26
Classifying Tr affic by Using ACLs 30-27
Classifying Tr affic by Using Class Maps 30-30
Classifying, Policing, and Marking Traffic by Usi ng Policy Maps 30-31
Configuring CoS Map s 30-34
Configuring the CoS-to-DSCP Map 30-35
Configuring the DSCP-to-CoS Map 30-36
Configuring the Egress Queues 30-37
Configuring CoS Pr iority Queues 30-37
Configuring WR R Priority 30-38
Enabling the Expedite Queue and Configuring WRR Priority 30-38
Displaying Standard QoS Information 30-39
Standard QoS Configuration Examples 30-39
QoS Configuratio n for the Existing Wiring Closet 30-40
QoS Configuration for the Intelligent Wiring Closet 30-41
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CHAPTER
31 Configuring EtherChannels 31-1
Understanding EtherChannels 31-1
Understanding Po rt-Channel Interfaces 31-2
Understanding the Port Aggregation Protocol and Link Aggregation Protocol 31-3
PAgP and LACP Modes 31-4
Physical Learners and Aggregate-Port Learners 31-5
PAgP and LACP Interaction with Other Features 31-6
Understanding Load Balancing and Forwarding Meth ods 31-6
Configuring EtherChannels 31-7
Default EtherCha nnel Configuration 31-8
EtherChannel Con figuration Guidelines 31-8
Configuring Layer 2 EtherChannels 31-9
Configuring EtherChannel Load Balancin g 31-11
Configuring the PAgP Learn Method and Priority 31-12
Configuring the LACP Port Priority 31-12
Configuring Hot Standby Ports 31-13
Configuring the LACP System Priority 31-13
Displaying EtherChannel, PAgP, and LACP Status 31-14
CHAPTER
32 Troubleshooting 32-1
Using Recovery Procedures 32-1
Recovering from Corrupted Software 32-2
Recovering from Lost or Forgotten Passwords on Non-LRE Catalyst 2950 Switches 32-2
Recovering from Lo st or Forgotten Passwords on Catalyst 2950 LRE Switches 32-4
Password Recovery with Password Recovery Enabled 32-5
Procedure with Password Recovery Disabled 32-6
Recovering from Lost or Forgotten Passwords on Catalyst 2955 Switches 32-8
Recovering from a Command Switch Failure 32-10
Replacing a Failed Command Switch with a Cluster Member 32-11
Replacing a Failed Command Switch with Another Switch 32-12
Recovering from Lost Member Connectivity 32-14
Preventing Auton egotiation Mismatches 32-14
GBIC and SFP Module Secur ity and Identification 32-14
Diagnosing Connec tivity Problems 32-15
Using Ping 32-15
Understanding Ping 32-15
Executing Ping 32-15
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Using Layer 2 Tr ac e route 32-16
Understanding Layer 2 Traceroute 32-16
Usage Guidelines 32-17
Displaying the Ph ysical Path 32-18
Diagnosing LRE Connection Problems 32-18
Using Debug Commands 32-19
Enabling Debuggi ng on a Specific Feature 32-20
Enabling All-System Diagnostics 32-20
Redirecting Debu g and Error Message Output 32-21
Using the debug auto qos Command 32-21
Using the show controllers Commands 32-22
Using the crashinfo File 32-23
APPENDIX
A Supported MIBs A-1
MIB List A-1
Using FTP to Access th e MI B Files A-3
APPENDIX
B Working with the Cisco IOS File Syst em, Configuration Files, and Software I ma ges B-1
Working with th e Fl ash 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 Directo ries and Displaying the Working Directory B-4
Creating and Removing Directories B-4
Copying Files B-5
Deleting Files B-5
Creating, Displaying, and Extracting tar Files B-6
Creating a tar File B-6
Displaying the Co ntents of a tar File B-7
Extracting a ta r Fil e 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-10
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-11
Downloading the Con figuration File By Using TFTP B-11
Uploading the Configuration File By Using TFTP B-12
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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 Confi guration 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 Confi guration File By Using RCP B-18
Clearing Configuration Information B-19
Clearing the St a rtu p Co nfiguration Fi le B-19
Deleting a Stored Configuration File B-19
Working with So ft w a re Ima g es 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 Downl oad or Upload an Image File By Using TFTP B-21
Downloading an Image File By Using TFTP B-22
Uploading an Image Fi le By Using TFTP B-23
Copying Image Files By Using FTP B-24
Preparing to Downl oad or Upload an Image File By Using FTP B-24
Downloading an Image File By Using FTP B-25
Uploading an Image Fi le By Using FTP B-27
Copying Image Files By Using RCP B-28
Preparing to Downl oad or Upload an Image File By Using RCP B-28
Downloading an Image File By Using RCP B-29
Uploading an Image File By Using RCP B-31
I
NDEX
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Preface
Audience
This guide is for the networking professional man aging the Catalyst 2950 and 2955 switches, hereafte r
referred to as the switches. Before using this guide, you should have experience working with the Cisco
IOS and be familiar with the concepts and terminology of Ethernet and local area networking.
Purpose
This guide provide s t he infor ma ti on you ne e d to configu re soft ware fea ture s o n y our swi tch . Th e
Catalyst 2950 switch is supported by either the standard software image (SI) or the enhan ced software image
(EI). The Catalyst 2955 and Catalyst 2950 Long-R each Ethernet (LRE) switches are supported only by the EI.
The EI provides a richer set of features, including access control lists (ACLs), enhanced quality of service
(QoS) features, extended-range VLANs, Remote Switched Port Analyzer (RSPAN), and unicast MAC
address filtering. The cryptographic EI provides support for the Secure Shell Protocol (SSP). For a list of
switches that support the SI and the EI, see Table 1-1 in Chapter 1, “Overview.”
The Catalyst 2955 switch also supports an additional set of features that are described in Chapter 3,
“Configuring Catalyst 2955 Switch Alarms. ” The switch has facilities to process alarms related to the
temperature, power supply cond itions, and status of the Ethern et ports.
Use this guide with other documents for information about these topics:
• Requirements—This guide assumes that you have met the hardware and software requirements and
cluster compatibility requirements described in the release notes.
• Start-up information —This guid e assume s that you have assigned switch IP informat ion and
passwords by using the browser setup pro gra m des cr ibed in t he swit ch ha rd ware insta ll ation g uide .
• Cluster Management Suit e (CMS) info rmation— This gui de provides an overview of the CMS
web-based, switch mana geme nt int erface. For inf ormat ion a bout CMS r equi reme nts an d the
procedures for browser and plug-in configuration and accessing CMS, refer to the release notes. For
CMS field-level window descriptions and procedures, re fer to th e CMS online he lp.
• Cluster configuration—Thi s guide provid es inform ation abou t planning for, creating, and
maintaining switch clusters. Because configuring switch clusters is most easily performed through
CMS, this guide does not provide the command-line interface (CLI) procedures. For the cluster
commands, refer to the comm and re ferenc e for th is releas e.
• CLI command information—This guide provides an overview for using the CLI. For complete
syntax and usage information about the commands that have been specifically created or changed
for the switches, re fer to th e comm and ref erence for this re lease .
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Preface
Conventions
This guide provides procedures for using the commands that have been created or changed for use with
the switch. It does not provide detailed information about these commands. For detailed information
about these comm ands , refer t o the co mman d refere nce for this rel ease .
This guide does not repe at the conc epts and CLI proce dures provided in the st andar d Cisco IOS
Release 12.1 docume ntation . For informati on about th e standa rd Cisco IOS Relea se 12.1 com mands,
refer to the Cisco IOS documentation set available from the Cisco.com home page at Service and
Support > Technical Documents. On the Cisco Product Documentation home page, select Release 12.1
from the Cisco IOS Software drop-down list.
This guide does not descri be system message s you might enc ounter or how to install your switch. For
this information, refer to the system message guide for this release and to the hardware installation
guide.
Conventions
This publication use s the se conventions to co nvey instructions a nd info rmat ion:
Command descriptions use these conventions:
• 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.
Interactive examples use these conventions:
• Terminal sessions and system displays are in screen font.
• Information you ent er is in b oldface sc reen f ont .
• Nonprinting charac ters, such as passwords or t abs, ar e in angl e brackets (< >) .
Notes, cautions, and timesavers use these conventions and symbols:
Note Means reader take note. Notes contain helpful suggestions or references to materials not contained in
this manual.
Caution Means re ader be careful. In this situation, you might do something that could result in equipment
damage or loss of data.
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