Cisco DOC-7814982 User Manual
Catalyst 2950 Desktop Switch Software
Configuration Guide
Cisco IOS Release 12.1(11)EA1 and 12.1(11)YJ
November 2002
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Catalyst 2950 Desktop Switch Software Configuration Guide
Copyright © 2001-2002, Cis co Sys tems, In c.
All rights reserved.
Preface xxv
Audience xxv
Purpose xxv
Organization xxvi
Conventions xxviii
Related Publications xxix
Obtaining Documentation xxix
World Wide Web xxix
Documentation CD-ROM xxx
Ordering Documentation xxx
Documentat ion Feedback xxx
Obtaining Technical Assistance xxx
Cisco.com xxxi
Technical Assistance Center xxxi
Cisco TAC Website xxxi
Cisco TAC Escalation Center xxxii
CONTENTS
CHAPTER
1 Overview 1-1
Features 1-1
Management Options 1-7
Management Interf ace Options 1-7
Advantage s of Us in g CMS and Cluster ing Switches 1-7
Network Configuration Examples 1-8
Design Concepts for Using the Switch 1-8
Small to Medium-Sized Network Configuration 1-11
Collapsed Backbone and Switch Cluster Configuration 1-13
Large Campus Configuration 1-14
Hotel Network Confi guration 1-16
Multidwelling Network Using Catalyst 2950 Switches 1-18
Long-Distance, High-Bandwidth Transport Configuration 1-20
Where to Go Next 1-21
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CHAPTER
2 Using the Command-Line Interface 2-1
IOS Command Modes 2-1
Getting Help 2-3
Specifying Ports in Interface Configuration Mode 2-4
Abbreviating Commands 2-5
Using no and default Forms of Commands 2-5
Understanding CLI Messages 2-5
Using Command History 2-6
Changing the Command Hi story Buffer Size 2-6
Recalling Commands 2-6
Disabling the Command History Feature 2-7
Using Editing Features 2-7
Enabling and Disa bling Editing Features 2-7
Editing Commands through Keystrokes 2-8
Editing Command Lines that Wrap 2-9
Searching and Filtering Output of show and more Commands 2-10
Accessing the CLI 2-10
CHAPTER
Accessing the CLI from a Browser 2-11
3 Getting Started with CMS 3-1
Features 3-2
Front Panel View 3-4
Cluster Tree 3-6
Front-Panel Ima ges 3-7
Redundant Power System LED 3-8
Port Modes and LEDs 3-8
VLAN Membership Modes 3-9
Topology View 3-10
Topology Icons 3-12
Device and Link Labe ls 3-13
Colors in the Topol ogy View 3-14
Topology Display Options 3-15
Menus and Toolbar 3-15
Menu Bar 3-15
Toolbar 3-20
Front Panel View Popup Menus 3-21
Device Popup Menu 3-21
Port Popup Menu 3-21
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Topology View Popup Menus 3-22
Link Popup Menu 3-22
Device Popup Menus 3-23
Interaction Modes 3-25
Guide Mode 3-25
Expert Mode 3-25
Wizards 3-26
Tool Tips 3-26
Online Help 3-26
CMS Window Components 3-28
Host Name List 3-28
Tabs, Lists, and Tables 3-29
Filter Editor 3-29
Icons Used in Windows 3-29
Buttons 3-30
Contents
CHAPTER
Accessing CM S 3-30
Access Modes in CMS 3-31
HTTP Access to CMS 3-32
Verifying Your Changes 3-32
Change Notification 3-32
Error Checkin g 3-32
Saving Your Configuration 3-33
Restoring Your Configuration 3-33
CMS Preferences 3-33
Using Different Versions of CMS 3-34
Where to Go Next 3-34
4 Assigning the Switch IP Address and Default Gateway 4-1
Understanding the Boot Process 4-1
Assigning Switch Information 4-2
Default Switch Information 4-3
Understanding DHCP-Based Autoconfiguration 4-3
DHCP Client Request Process 4-4
Configuring the DHCP Server 4-5
Configuring the TFTP Server 4-5
Configuring the DNS 4-6
Configuring the Relay Device 4-6
Obtaining Configuration Files 4-7
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Example Configuration 4-8
Manually Assigning IP Information 4-10
Checking and Saving the Running Configuration 4-10
CHAPTER
5 Configuring IE2100 CNS Agents 5-1
Understanding IE2100 Series Configuration Registrar Software 5-1
CNS Configuration Service 5-2
CNS Event Service 5-3
NameSpace M a pper 5-3
What You Should Know About ConfigID, DeviceID, and Host Name 5-3
ConfigID 5-3
DeviceID 5-4
Host Name and DeviceID 5-4
Using Host Name, DeviceID, and ConfigID 5-4
Understanding CNS Embedded Agents 5-5
Initial Configuration 5-5
Incremental (P ar tial) Configurat ion 5-6
Synchronized Configuration 5-6
Configuring CNS Embe dded Agents 5-6
Enabling Automate d CNS Configuration 5-6
Enabling the CNS Event Agent 5-8
Enabling the CNS Configuration Agent 5-9
Enabling an Initial Configuration 5-9
Enabling a Partial Configuration 5-12
CHAPTER
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Displaying CNS Configuration 5-13
6 Clustering Switches 6-1
Understanding Switch Clusters 6-2
Command Switch Characteristics 6-3
Standby Command Switch Characteristics 6-3
Candidate Switch and Member Switch Characteristics 6-4
Planning a Switch Cluster 6-5
Automatic Discovery of Cluster Candidates and Members 6-5
Discovery th ro ug h CD P H op s 6-6
Discovery through Non-CDP-Capable and Noncluster-Capable Devices 6-7
Discovery through the Same Management VLAN 6-8
Discovery through Di fferent Management VLANs 6-9
Discovery of Newly Installed Switches 6-10
HSRP and Standby Command Switches 6-12
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Virtual IP Addres s es 6-13
Other Considerations for Cluster Standby Groups 6-13
Automatic Recovery of Cluster Configuration 6-15
IP Addresses 6-15
Host Names 6-16
Passwords 6-16
SNMP Community Strings 6-16
TACACS+ and RADIUS 6-17
Access Modes in CMS 6-17
Management VLAN 6-18
LRE Profiles 6-18
Availability of Switch-Specific Features in Switch Clusters 6-19
Creating a Switch Cluster 6-19
Enabling a Command Switch 6-19
Adding Member Switches 6-20
Creating a Cluster Standby Group 6-22
Verifying a Switch Cl uster 6-24
Contents
CHAPTER
Using the CLI to Manage Switch Clusters 6-25
Catalyst1900 and Catalyst2820 CLI Considerations 6-25
Using SNMP to Manage Sw itch Clusters 6-26
7 Administering the Switch 7-1
Preventing Unautho rized Access to Your Switch 7-1
Protecting Access to Privileged EXEC Commands 7-2
Default Password and Privilege Level Configuration 7-2
Setting or Changing a Static Enable Password 7-3
Protecting Enable and Enable Secret Passwords with Encryption 7-4
Disabling Password Recovery 7-5
Setting a Telnet Password for a Terminal Line 7-6
Configuring User name and Password Pairs 7-7
Configuring Multiple Privilege Lev e ls 7-8
Setting the Priv ilege Level for a Command 7-8
Changing the Default Privilege Level for Lines 7-9
Logging into and Exiting a Privilege Level 7-10
Controlling Switch Access with TACACS+ 7-10
Understanding TACACS+ 7-10
TACACS+ Operation 7-12
Configuring TACACS+ 7-12
Default TACACS+ Confi guration 7-13
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Identifying the TACACS+ Server Host and Setting th e Authentication Key 7-13
Configuring TACACS+ Login Authentication 7-14
Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 7-16
Starting TACACS+ Accounting 7-17
Displaying the TA CACS+ Configuration 7-17
Controlling Switch Access with RADIUS 7-18
Understanding RADIUS 7-18
RADIUS Operation 7-19
Configuring RADIUS 7-20
Default RADIUS Configu ration 7-20
Identifying the RADIUS Server Host 7-20
Configuring RADI US Login Authentication 7-23
Defining AAA Server Groups 7-25
Configuring RADIUS Authorization for User Privileged Access and Network Services 7-27
Starting RADIUS Accounting 7-28
Configuring Set tings for All RADIUS Servers 7-29
Configuring the Switch to Use Vendor-Specific RADIUS Attributes 7-29
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 7-30
Displaying the RADIUS Configuration 7-31
Configuring the Switch for Local Authenticat ion and Authorization 7-32
Configuring the Switch for Secure Shell 7-33
Understanding SSH 7-33
Configuring SSH 7-33
Managing the System Time and Date 7-34
Understanding the System Clock 7-34
Understanding Network Time Protocol 7-34
Configuring NTP 7-36
Default NTP Config uration 7-37
Configuring NTP Authentication 7-37
Configuring NTP Associations 7-38
Configuring NTP Broadcast Service 7-39
Configuring NTP Ac cess Restrictions 7-40
Configuring the Source IP Address for NTP Packets 7-42
Displaying the NTP C onfiguration 7-43
Configuring Ti me and Date Manually 7-43
Setting the System Clock 7-44
Displaying the Time and Date Configuration 7-44
Configuring the Time Zone 7-45
Configuring Summer Time (Daylight Saving Time) 7-46
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Configuring a System Name and Prompt 7-48
Default System Name and Prompt Configuration 7-48
Configuring a System Name 7-48
Configuring a System Prompt 7-49
Understanding DNS 7-49
Default DNS Configuration 7-50
Setting Up DNS 7-50
Displaying the DNS Configuration 7-51
Creating a Banner 7-51
Default Banner Con figuration 7-51
Configuring a Message-of-the-Day Login Banner 7-52
Configuring a Login Banner 7-53
Managing the MAC Address Table 7-54
Building the Address Table 7-54
MAC Addresses and VLANs 7-55
Default MAC Address Tab le Configuration 7-55
Changing the Addres s Aging Time 7-55
Removing Dynamic Address Entries 7-56
Configuring MAC Address Notification Traps 7-56
Adding and Removing Static Address Entries 7-58
Adding and Removing Secure Addresses 7-59
Displaying Addre ss Table Entries 7-60
Contents
CHAPTER
Managing the ARP Table 7-61
Switch Software Releases 7-61
8 Configuring 802.1X Port-Based Authentication 8-1
Understanding 802.1X Port-Based Authenticati on 8-1
Device Roles 8-2
Authentication Initiation and Message Exchange 8-3
Ports in Authorized and Unauthorized States 8-4
Supported Topologies 8-5
Configuring 802.1X Authentication 8-5
Default 802.1X Configuration 8-6
802.1X Configur ation Guidelines 8-7
Enabling 802.1X Authentication 8-8
Configuring th e Switch-to-RADIUS-Server Communication 8-9
Enabling Periodic Re-Authentication 8-10
Manually Re-Authenticating a Client Connected to a Port 8-11
Changing the Quiet Period 8-11
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Changing the Switch-to-Client Retransmission Time 8-12
Setting the Switch-to-Client Frame-Retransmission Number 8-13
Enabling Multiple Hosts 8-13
Resetting the 802 .1X Configuration to the Default Values 8-14
Displaying 802.1X Statistics and Status 8-14
CHAPTER
9 Configuring the Switch Interfaces 9-1
Understanding Interface Types 9-1
Access Ports 9-2
Trunk Ports 9-2
Port-Based VLANs 9-3
EtherChannel Por t Groups 9-3
Connecting Interfaces 9-3
Using the Interface Command 9-4
Procedures for Configuring Interfaces 9-4
Configuring a Range of Interfaces 9-6
Configuring and Using Interface-Range Macros 9-8
Configuring Switch Interfaces 9-9
Default Etherne t Interface Configuration 9-10
SFP Configuration 9-10
Configuring Interface Speed and Duplex Mode 9-11
Configuration Guidelines 9-12
Setting the Interface Speed and Duplex Parameters 9-13
Configuring Media Types for Gigabit Interfaces 9-14
Configuring IEEE 802.3X Flow Control on Gigabit Ethernet Ports 9-14
Adding a Descripti on for an Interface 9-16
CHAPTER
x
Monitoring and Maintaining the Interfaces 9-16
Monitoring Interface and Controller Status 9-16
Clearing and Reset ting Interfaces and Counte rs 9-19
Shutting Down and Restarting the Interface 9-19
10 Configuring LRE 10-1
Ports on the 295 0 LR E 10-1
LRE Links and LRE Profil es 10-2
LRE Profiles 10-2
LRE Sequences 10-4
CPE Ethernet Links 10-5
Configuring LRE Ports 10-5
Environmental Guidelines for LRE Links 10-6
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Guidelines for Us ing LRE Profiles 10-7
CPE Ethernet Link Guidelines 10-7
Considerations for Connected Cisco 575 LRE CPEs 10-7
Considerations for Connected Cisco 585 LRE CPEs 10-8
Assigning a Global Profile to All LRE Ports 10-8
Assigning a Profile to a Specific LRE Port 10-9
Assigning a Global Sequence to All LRE Ports 10-9
Assigning a Sequence to a Specific LRE Port 10-10
Using Rate Selection to Automatically Assign Profiles 10-10
Precedence 10-11
Profile Lockin g 10-11
Link Qualification and SNR Margins 10-12
LRE Link Persist ence 10-14
LRE Link Monitor 10-14
Upgrading LRE Switch Firmware 10-15
Configuring for an LRE Upgrade 10-15
Performing an LRE Upgrade 10-16
Global Configuration of LRE Upgrades 10-17
Controller Configuration of LRE Upgrades 10-17
LRE Upgrade Behavior Details 10-18
LRE Upgrade Example 10-18
Contents
CHAPTER
11 Configuring STP 11-1
Understanding Spanning-Tree Features 11-1
STP Overview 11-2
Supported Spanning-Tree Instances 11-2
Bridge Protocol Data Units 11-2
Election of the Root Switch 11-3
Bridge ID, Switch Priority, and Extended System ID 11-4
Spanning-Tree Timers 11-4
Creating the Spann ing-Tree Topology 11-5
Spanning-Tree I nterface States 11-5
Blocking State 11-7
Listening State 11-7
Learning State 11-7
Forwarding State 11-7
Disabled State 11-8
Spanning-Tree Add ress Management 11-8
STP and IEEE 802.1Q Tr unks 11-8
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Spanning Tree and Redundant Connectivity 11-8
Accelerated Aging to Retain Connectivity 11-9
Configuring Spanning-Tree Features 11-9
Default STP Confi guration 11-10
STP Configuration Guidelines 11-10
Disabling STP 11-12
Configuring the Root Switch 11-12
Configuring a Sec ondary Root Switch 11-14
Configuring the Port Priority 11-15
Configuring the Path Cost 11-16
Configuring the Switch Priority of a VLAN 11-18
Configuring the Hello Time 11-19
Configuring th e Forwarding-Delay Time for a VLAN 11-19
Configuring th e Maximum-Aging Time for a VLAN 11-20
Configuring STP for Use in a Cascaded Stack 11-20
CHAPTER
Displaying the Spanning-Tree Status 11-21
12 Configuring RSTP and MSTP 12-1
Understanding RSTP 12-2
Port Roles and the Active Topology 12-2
Rapid Convergence 12-3
Synchronization of Port Roles 12-4
Bridge Protocol Data Unit Format and Processing 12-5
Processing Super ior BPDU Information 12-6
Processing Inferior BPDU Information 12-6
Topology Changes 12-6
Understanding MSTP 12-7
Multiple Spanning-Tree Regions 12-7
IST, CIST, and CST 12-8
Operations Within an MST Region 12-8
Operations Betwee n MST Regions 12-9
Hop Count 12-10
Boundary Ports 12-10
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Interoperability with 802.1D STP 12-11
Configuring RSTP and MSTP Features 12-11
Default RSTP and MSTP Configuration 12-12
RSTP and MSTP Configuration Guidelines 12-12
Specifying the MST Region Configuration and Enabling MSTP 12-13
Configuring the Root Switch 12-14
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Configuring a Secondary Root Switch 12-16
Configuring the Port Priority 12-17
Configuring the Path Cost 12-18
Configuring the Switch Priority 12-19
Configuring the Hello Time 12-19
Configuring the Forwarding-Delay Time 12-20
Configuring th e Maximum-Aging Time 12-21
Configuring the Maximum-Hop Count 12-21
Specifying the Link Type to Ensure Rapid Transiti ons 12-22
Restarting the Protocol Migration Process 12-22
Displaying the MST Configuration and Status 12-23
Contents
CHAPTER
13 Configuring Optional Spanning-Tree Features 13-1
Understanding Optional Spanning-Tree Features 13-1
Understanding Po rt Fast 13-2
Understanding BPD U Guard 13-3
Understanding BPDU Filtering 13-3
Understanding UplinkFast 13-4
Understanding Cross-Stack UplinkFast 13-5
How CSUF Works 13-6
Events That Cause Fast Convergence 13-7
Limitations 13-8
Connecting the Stack Ports 13-8
Understanding BackboneFast 13-10
Understanding Root Guard 13-12
Understanding Loop Guard 13-13
Configuring Optional Spanning-Tree Features 13-13
Default Optional Spanning-Tree Configuration 13-14
Enabling Port Fast 13-14
Enabling BPDU Guard 13-15
Enabling BPDU Filtering 13-16
Enabling Uplink Fast for Use with Redundant Links 13-17
Enabling Cross-Stack UplinkFast 13-18
Enabling BackboneFast 13-19
Enabling Root Guard 13-19
Enabling Loop Guard 13-20
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Displaying the Spanning-Tree Status 13-21
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14 Configuring VLANs 14-1
Understanding VLANs 14-1
Supported VLANs 14-2
VLAN Port Membership Modes 14-3
Configuring Nor mal-Range VLANs 14-4
Token Ring VLANs 14-5
Normal-Range VLAN Configuration Guidelines 14-5
VLAN Configuration Mode Options 14-6
VLAN Configuration in config-vlan Mode 14-6
VLAN Configuration in VLAN Configuration Mode 14-6
Saving VLAN Configuration 14-7
Default Etherne t VLAN Configuration 14-8
Creating or Modifying an Ethernet VLAN 14-8
Deleting a VLAN 14-10
Assigning St at ic-Access Port s to a VLAN 14-11
Configuring Ext ended-Range VLANs 14-12
Default VLAN Configuration 14-12
Extended-Range VLAN Configuration Guidelines 14-12
Creating an Extended-Range VLAN 14-13
Displaying VLANs 14-14
Configuring VLAN Tr unks 14-15
Trunking Overview 14-15
802.1Q Configura tion Considerations 14-16
Default Layer 2 Ethernet Inte rfa c e VL A N Co nf ig uration 14-17
Configuring an Ethernet Interface as a Trunk Port 14-17
Interaction with Other Features 14-17
Configuring a Trunk Port 14-18
Defining the Allo w e d V LA N s on a Tr un k 14-19
Changing the Pruning-Eligible List 14-20
Configuring the Native VLAN for Untagged Traffic 14-20
Load Sharing Using STP 14-21
Load Sharing Using STP Port Priorities 14-21
Load Sharing Using STP Path Cost 14-23
Configuring VMPS 14-24
Understanding VMPS 14-25
Dynamic Port VLAN Membership 14-25
VMPS Databa se Co nfiguration Fi le 14-26
Default VMPS Configuration 14-27
VMPS Configu ra tion Guidelines 14-28
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Configuring the VMPS Client 14-28
Entering the IP Address of the VMPS 14-28
Configuring Dynamic Access Ports on VMPS Clients 14-29
Reconfirming VLAN Memberships 14-30
Changing the Reconfirmation Interval 14-30
Changing the Retry Count 14-30
Monitoring the VMPS 14-31
Troubleshooting Dynamic Port VLAN Membership 14-31
VMPS Configuration Example 14-32
Contents
CHAPTER
15 Configuring VTP 15-1
Understanding VTP 15-1
The VTP Domain 15-2
VTP Modes 15-3
VTP Advertisements 15-3
VTP Version 2 15-4
VTP Pruning 15-4
Configuring VTP 15-6
Default VTP Confi guration 15-6
VTP Configuration Options 15-7
VTP Configuration in Global Configuration Modes 15-7
VTP Configuration in VLAN Configuration Mode 15-7
VTP Configuration Guidelines 15-8
Domain Names 15-8
Passwords 15-8
Upgrading from Pr evious Softwa re Re le ases 15-8
VTP Version 15-9
Configuration Requirements 15-9
Configuring a VTP Server 15-9
Configuring a VTP Client 15-11
Disabling VTP (VTP Transparent Mode) 15-12
Enabling VTP Version 2 15-13
Enabling VTP Pruning 15-14
Adding a VTP Client Switch to a VTP Domain 15-15
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Monitoring VTP 15-16
16 Configuring Voice VLAN 16-1
Understanding Voice VLAN 16-1
Configuring Voi ce VLAN 16-2
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Default Voice VLAN Configuration 16-2
Voice VLAN Config uration Guidelines 16-3
Configuring a Port to Connect to a Cisco7960 IP Phone 16-3
Configuring Ports to Carry Voice Traffic in 802.1Q Frames 16-4
Configuring Ports to Carry Voice Traffic in 802.1P Priority Tagged Frames 16-4
Overriding the CoS Priority of Incoming Data Frames 16-5
Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames 16-6
Displaying Voic e VLAN 16-6
CHAPTER
17 Configuring IGMP Snooping and MVR 17-1
Understanding IGMP Snooping 17-1
Joining a Multicast Group 17-2
Leaving a Multicast Group 17-4
Immediate-Leave Processing 17-4
Configuring IGMP Snooping 17-5
Default IGMP Snoo ping Configuration 17-5
Enabling or Dis a bl in g IG M P Sno o pi ng 17-5
Setting the Snooping Method 17-6
Configuring a Multicast Router Port 17-7
Configuring a Host Statically to Join a Group 17-8
Enabling IGMP Immediate-Leave Processing 17-9
Disabling IP Multicast-Source-Only Learning 17-9
Displaying IGMP Sno oping Information 17-11
Understanding Multicast VLAN Registration 17-13
Using MVR in a Multicast Television Application 17-13
Configuring MV R 17-15
Default MVR Configuration 17-15
MVR Configuration Guidelines and Limitations 17-16
Configuring MVR Global Parameters 17-16
Configuring MV R Interfaces 17-17
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Displaying MVR Information 17-19
Configuring IGMP Filtering 17-20
Default IGMP Filtering Configuration 17-21
Configuring IGMP Profiles 17-21
Applying IGMP Profil es 17-22
Setting the Maximum Number of IGMP Groups 17-23
Displaying IGMP Filtering Configuration 17-24
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CHAPTER
18 Configuring Port-Based Traffic Control 18-1
Configuring Sto rm Control 18-1
Understanding Storm Control 18-1
Default Storm Control Configuration 18-2
Enabling Storm Control 18-2
Disabling Storm Control 18-3
Configuring Protected Ports 18-3
Configuring Port Security 18-4
Understanding Po rt Security 18-5
Secure MAC Addresses 18-5
Security Viol at ions 18-6
Default Port Security Configuration 18-7
Port Security Configuration Guidelines 18-7
Enabling and Configuring Port Security 18-7
Enabling and Confi guring Port Security Aging 18-10
Displaying Port -Based Traffic Control Settings 18-12
19 Configuring UDLD 19-1
CHAPTER
CHAPTER
Understanding UDLD 19-1
Configuring UDLD 19-3
Default UDLD Configuration 19-3
Enabling UDLD Globally 19-4
Enabling UDLD on an Interface 19-4
Resetting an Interface Shut Down by UDLD 19-5
Displaying UDLD Status 19-6
20 Configuring CDP 20-1
Understanding CDP 20-1
Configuring CDP 20-2
Default CDP Config uration 20-2
Configuring the CDP Characteristics 20-2
Disabling and Enabling CDP 20-3
Disabling and Enabling CDP on an Interface 20-4
Monitoring and Maintaining CDP 20-5
21 Configuring SPAN and RSPAN 21-1
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Understanding SPAN and RSPAN 21-1
SPAN and RSPAN Concepts and Terminology 21-3
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SPAN Session 21-3
Traffic Typ es 21-3
Source Port 21-4
Destination Por t 21-5
Reflector Port 21-5
VLAN-Based SPAN 21-6
SPAN Traffic 21-6
SPAN and RSPAN Interaction with Other Features 21-7
SPAN and RSPAN Session Limit s 21-8
Default SPAN and RSPAN Conf iguration 21-8
Configuring SPAN 21-8
SPAN Configuration Guidelines 21-8
Creating a SPAN Session and Specifying Ports to Monitor 21-9
Removing Ports from a SPAN Se ss io n 21-11
Specifying VLANs to Monitor 21-12
Specifying VLANs to Filter 21-13
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Configuring RSPAN 21-14
RSPAN Configuration Guidelines 21-14
Creating an RSPAN Session 21-15
Creating an RSPAN Destination Session 21-16
Removing Ports from an RSPAN Se s sion 21-17
Specifying VLANs to Monitor 21-18
Specifying VLANs to Filter 21-19
Displaying SPAN and RSPAN Status 21-20
22 Configuring RMON 22-1
Understanding RMON 22-1
Configuring RMON 22-2
Default RMON Configuration 22-3
Configuring RMON Alarms and Events 22-3
Configuring RMON Col lection on an Interface 22-5
Displaying RMON Status 22-6
23 Configuring System Message Logging 23-1
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Understanding System Message Logging 23-1
Configuring System Message Logging 23-2
System Log Message Format 23-2
Default System Message Logging Configuration 23-3
Disabling and Enabling Message Logging 23-4
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Setting the Message D isplay Destination Device 23-4
Synchronizing Log Messages 23-6
Enabling and Disa bling Timestamps on Log Messages 23-7
Enabling and Disabling Sequence Numbers in Log Messages 23-8
Defining the Message Severity Level 23-8
Limiting Syslog Messages Sent to the History Table and to SNMP 23-10
Configuring UNIX Syslog Servers 23-10
Logging Messages to a UNIX Syslog Daemon 23-11
Configuring the UNIX System Logging Facility 23-11
Displaying the Lo gging Configuration 23-12
Contents
CHAPTER
24 Configuring SNMP 24-1
Understanding SNMP 24-1
SNMP Versions 24-2
SNMP Manager Functions 24-3
SNMP Agent Fu nc ti on s 24-3
SNMP Community Strings 24-4
Using SNMP to Access MIB Variables 24-4
SNMP Notifications 24-5
Configuring SNMP 24-5
Default SNMP Configuration 24-6
SNMP Configuration Guidelines 24-6
Disabling the SNMP Agent 24-7
Configuring Commun ity Strings 24-7
Configuring SNMP Groups and Users 24-8
Configuring SNMP Notifications 24-10
Setting the Agent Contact and Location Informat ion 24-13
Limiting TFTP Servers Used Through SNMP 24-13
SNMP Exampl es 24-14
CHAPTER
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Displaying SNMP Status 24-15
25 Configuring Network Security with ACLs 25-1
Understanding ACLs 25-2
Handling Fragmented and Unfragmented Traffic 25-3
Understanding Access Control Parameters 25-4
Guidelines for Applying ACLs to Physical Interfaces 25-6
Configuring ACLs 25-6
Unsupported Features 25-7
Creating Standard and Extended IP ACLs 25-7
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Contents
ACL Numbers 25-8
Creating a Numbered Standard ACL 25-9
Creating a Numbered Extended ACL 25-10
Creating Named Standard and Extended ACLs 25-13
Applying Time Ranges to ACLs 25-15
Including Comments About Entries in ACLs 25-17
Creating Named MAC Extended ACLs 25-18
Creating MAC Access Groups 25-19
Applying ACLs to Terminal Lines or Physical Interfaces 25-20
Applying ACLs to a Terminal Line 25-20
Applying ACLs to a Physical Interface 25-21
Displaying ACL In formation 25-21
Displaying ACLs 25-22
Displaying Access Groups 25-23
Examples for Compiling ACLs 25-23
Numbered ACL Examples 25-25
Extended ACL Examples 25-25
Named ACL Example 25-25
Commented IP AC L En tr y Exa m ples 25-25
CHAPTER
26 Configuring QoS 26-1
Understanding QoS 26-2
Basic QoS Model 26-3
Classification 26-4
Classification Based on QoS ACLs 26-5
Classification Based on Class Maps and Policy Maps 26-6
Policing and Marking 26-6
Mapping Tables 26-7
Queueing and Scheduling 26-7
How Class of Service Works 26-7
Port Priority 26-8
Port Scheduling 26-8
CoS and WRR 26-8
Configuring QoS 26-9
Default QoS Config uration 26-9
Configuratio n Guidelines 26-10
Configuring Classification Using Port Trust States 26-10
Configuring the Trust State on Ports within the Q oS Domain 26-11
Configuring the CoS Value for an Interface 26-13
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Configuring Trusted Boundary 26-13
Enabling Pass-Through Mode 26-15
Configuring a QoS Policy 26-16
Classifying Tr affic by Using ACLs 26-16
Classifying Tr affic by Using Class Maps 26-20
Classifying, Policing, and Marking Traffic by Using Policy Maps 26-21
Configuring CoS Map s 26-24
Configuring the CoS-to-DSCP Map 26-25
Configuring the DSCP-to-CoS Map 26-26
Configuring CoS an d WRR 26-27
Configuring CoS Pr iority Queues 26-27
Configuring WR R 26-27
Displaying QoS Information 26-28
QoS Configuration Examples 26-29
QoS Configuratio n for the Existing Wiring Closet 26-30
QoS Configuration for the Intelligent Wiring Closet 26-30
Contents
CHAPTER
CHAPTER
27 Configuring EtherChannels 27-1
Understanding EtherChannels 27-1
Understanding Po rt-Channel Interfaces 27-2
Understanding the Port Aggregation Protocol 27-3
PAgP Modes 27-4
Physical Learners and Aggregate-Port Learners 27-5
PAgP Interaction with Other Features 27-5
Understanding Load Balancing and Forwarding Methods 27-5
Configuring EtherChannels 27-7
Default EtherCha nnel Configuration 27-7
EtherChannel Con figuration Guidelines 27-8
Configuring Layer 2 EtherChannels 27-8
Configuring EtherChannel Load Balancing 27-10
Configuring the PAgP Learn Method and Priority 27-11
Displaying EtherChannel and PAgP Status 27-11
28 Troubleshooting 28-1
LRE Statistics 28-1
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Using Recovery Procedures 28-6
Recovering from Corrupted Software 28-6
Recovering from a Lost or Forgotten Password 28-6
Recovering from a Command Switch Failure 28-8
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Contents
Replacing a Failed Command Switch with a Cluster Member 28-9
Replacing a Failed Command Switch with Another Switch 28-10
Recovering from Lost Member Connectivity 28-11
Preventing Auton egotiation Mismatches 28-12
Troubleshooting LRE Port Configuration 28-12
GBIC and SFP Module Secur ity and Identification 28-13
Using Debug Commands 28-14
Enabling Debuggi ng on a Specific Feature 28-14
Enabling All-System Diagnostics 28-15
Redirecting Debu g and Error Message Output 28-15
Using the crashinfo File 28-15
APPENDIX
APPENDIX
A Supported MIBs A-1
MIB List A-1
Using FTP to Access th e MI B Files A-2
B Working with the IOS File System, Configuration Files, and Software Images 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
xxii
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-11
Preparing to Download or Upload a Configuration File By Using TFTP B-11
Downloading the Con figuration File By Using TFTP B-12
Uploading the Configuration File By Using TFTP B-12
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Copying Configuration Files By Using FTP B-13
Preparing to Download or Upload a Configuration File By Using FTP B-13
Downloading a Configuration File By Using FTP B-14
Uploading a Confi guration File By Using FTP B-15
Copying Configuration Files By Using RCP B-16
Preparing to Download or Upload a Configuration File By Using RCP B-17
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-20
Working with So ft w a re Ima g es B-20
Image Location on the Switch B-20
tar File Format of Images on a Server or Cisco.com B-21
Copying Image Files By Using TFTP B-22
Preparing to Downl oad or Upload an Image File By Using TFTP B-22
Downloading an Image File By Using TFTP B-23
Uploading an Image Fi le By Using TFTP B-24
Copying Image Files By Using FTP B-25
Preparing to Downl oad or Upload an Image File By Using FTP B-25
Downloading an Image File By Using FTP B-26
Uploading an Image Fi le By Using FTP B-28
Copying Image Files By Using RCP B-29
Preparing to Downl oad or Upload an Image File By Using RCP B-29
Downloading an Image File By Using RCP B-30
Uploading an Image File By Using RCP B-32
Contents
I
NDEX
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Audience
Preface
The Catalyst 2 950 Desktop Switch Software Configuration G uide i s for t he n etwor k mana ger
responsible for configuring the Catalyst 2950 switches, hereafter referred to as the switches. Before
using this guide, you should be familiar with the concepts and terminology of Ethernet and local area
networking.
Purpose
This guide provides information about configuring and troubleshooting a Catalyst 2950 or Catalyst 2950
Long-Reach Ethe rnet (LRE) sw itch o r s witc h cl uste rs. It inc lude s d escri ption s of th e ma na geme nt
interface options and the features supported by the switch software. The non-LRE switch is supp o rted by
either the standard software image (SI) or the enhanced software image (EI). The EI provides a richer set of
features, including access control lists (ACLs), enhanced quality of service (QoS) features, the Secure Shell
Protocol, extended-range VLANs, and Remote Switch Port Analyzer (RSPAN). For a list of switches that
support the SI and the EI, see Table 1-1 on page 1. The 2950 LRE switch is suppo rted by an a v ariation of the
enhanced software image [12.1(11)LRE].
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 guide assumes that you have assigned switch IP info rmati on and
passwords by using the setup program descri bed in the rele ase notes .
• Cluster Management Sui te (CMS) i nformat ion—This guide provides an overview of the CMS
web-based, switch mana geme nt int erface. For inf orm ation a bout CMS r e quireme 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—This guide provides inform ation a bout planni ng 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.
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• 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 .
Catalyst 2950 Desktop Switch Software Configuration Guide
xxv
Organization
This guide does not descri be system message s you might enc ounter or how to install your switch. For
more inform ation, refer to the Catalyst 2950 Desktop Switch System Message Guide for this release and
to the Catalyst 2950 Desktop Sw itch Ha rdware Installation Guide .
Note 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 informa tion ab out the stan dard IO S Releas e 12.1 co mmands, re fer to
the IOS documen tation se t available fro m t he Ci sco.c om ho me p ag e at Service and Support >
T echni cal Documents. On t he Cisco Produ ct Documentation hom e page, select Release 12.1 from the Ci sco
IOS Software drop-down list.
Note This guide describes the featu res for Catalyst 295 0 sw itches. Cisco IOS Rel ease 12.1(11)EA1 is not for
use with the Long-Reach Ethernet (LRE) switches. Do not install release 12.1(11)EA1 on Catalyst 2950
LRE switches, and do not instal l releas e 12.1(11) YJ on non-LR E switches.
Organization
Preface
This guide is organized into these chapters:
Chapter 1, “Ove rv i ew,” lists the software features of this release and provides examples of how the
switch can be deployed in a network.
Chapter 2, “Using the Command-Line Interface,” describes how to access the command modes, use the
CLI, and describes CLI messa ges that you migh t receive. It also describes how to get help, abbr eviate
commands, use no and default forms of commands, use command history and editing features, and how
to search and filter the output of show and more commands.
Chapter 3, “Getting Started with CMS,” describes the CMS web-based , switch ma nagement interface.
For information about configuring your web browser and accessing CMS, refer to the release notes. For
field-level descriptions of all CMS wi ndows and pr oc edure s f or usi ng t h e CM S wi ndows, refer to the
online help.
Chapter 4, “Assigning the Switch IP Address and Default Gateway,” describes how to create the initial
switch configuration (for example, assign the switch IP address and default gateway information) by
using a variety of automatic and manua l metho ds.
Chapter 5, “Configuring IE2100 CNS Agents,” describes how to conf igure Cisco I ntelligence Engine 2 100
(IE2100) Series Cisco Networking Services (CNS) embedded agents on your switch. By using the
IE2100 Series Configuration Registrar network management application, you can automate initial
configurations and conf iguration upd ates by generatin g switch-specific con figuration changes, sending t hem
to the switch, executing the configuration change, and logging the results.
Chapter 6, “Clust ering Switches,” describes switch c luster s and the cons ider ation s for creat ing and
maintaining them. The online help provides the CMS procedures for configuring switch clusters.
Configuring switch cl usters is mo st e asily pe rfo rmed t hroug h C MS; th eref or e, CL I pr ocedu re s are not
provided. Cluster comman ds are de scribed in the Ca tal yst 295 0 De skto p S witch Comm an d Re ference.
xxvi
Chapter 7, “Administering the Switch,” descr ibes how to perform one-tim e operat ions to admi nister
your switch. It de scr ibes how to prevent una uthor ized ac cess to y our swit ch t hroug h t he use of
passwords, privilege levels, the Terminal Access Controller Access Control System Plus (TACACS+),
and the Remote Authenticat ion Dia l-In User Ser vice (RA DIUS) a nd the Sec ure Shell (SSH) Proto col. It
also describes how to set the syste m date an d ti me, set syste m n ame and pro mp t, c reate a lo gin ba nn er,
and how to manage the MAC address and Address Resolut ion Protocol (ARP) tabl es.
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Preface
Organization
Chapter 8, “Configuring 802.1X Port-Based Authentication,” d escri bes how to configu re 80 2.1X
port-based authenti ca tion to prevent unauthorized devices (clients) from gaining access to the network.
As LANs extend t o hote ls, air por ts , and c or por ate lob bi es , in sec ure environme nts cou l d b e cr ea te d.
Chapter 9, “Configuring the Switch Interfaces,” defines the types of interfaces on the switch. It describes
the interface global configuration comma nd an d prov ides pr ocedu re s f or c onfiguri ng physi cal
interfaces.
Chapter 10, “Configuring LRE,” describes how to configure LRE-spe cific fe ature s o n your sw itch .
Chapter 11, “Configuring STP,” describes how to configure the Spanning Tree Protocol (STP) on your
switch.
Chapter 12, “Configuring RSTP and MSTP,” describes how to configure the Cisco implementation o f
the IEEE 802.1W Rapid STP (RSTP) and the IEEE 802.1S Multiple STP (MSTP) on your switch. RSTP
provides rapid convergence, and M STP en ab les VLA Ns t o be g rou pe d in to a sp an ning- tre e i nstan ce .
Chapter 13, “Configuring Optional Spanning-Tree Features,” describes how to configure optional
spanning-tree featur es that can be used when you r switc h is running the per-VLAN spann ing-tr ee
(PVST) or the MS TP.
Chapter 14, “Configuring VLANs,” describes how to create and maintain VLANs. It includes
information about t he V LAN data base , VLAN c onfiguration m ode s, ext ende d-r ange VLA Ns , V LAN
trunks, and the VLAN Membership Policy Server (VMPS).
Chapter 15, “Configuring VTP,” describes how to use the VLA N Trunking Pro toco l (VT P) VLA N
database for managin g V LANs. I t inc ludes V T P cha racteri stic s and c onfiguration .
Chapter 16, “Configuring Voice VLAN,” describes how to configure voice VLANs on the switch for a
connection to an IP phone.
Chapter 17, “Configuring IGMP Snooping and MV R,” describes how to configure Intern et Group
Management Protocol (IGMP) snooping. It also describes Multicast VLAN Registration (MVR), a local
IGMP snooping fea tur e available on t he swit ch, and how to u se IG MP filterin g to c ontro l mul tica st
group membership.
Chapter 18, “Configuring Port-Based Traffic Control,” describes how to reduce traffic storms by setting
broadcast, multicast, and unicast storm-control threshold levels; how to protect ports from receiving
traffic from other ports on a switch; how to configure port security by using secure MAC addresses; and
how to set the aging time for all secure addresses.
Chapter 20, “Configuring CDP,” describes how to con figure C isco Di scovery Prot ocol (CD P) on you r
switch.
Chapter 21, “Configuring SPAN and RSPAN,” describes how to configure Switched Port Analyzer
(SPAN) and Remot e SPAN (RSPAN), which sel ect n e twork t r affic for analy si s by a ne twor k ana lyz er
such as a SwitchProbe device or other Remote Monitoring (RMON) probe.
Chapter 22, “Configuring RMON,” describes how to configure remote monitoring (RMON). The
RMON feature, which is used with the Simple Network Management Protocol (SNMP) agent in the
switch, means that you can monitor all the traffic flowing among switches on all connected LAN
segments.
Chapter 23, “Configuring System Message Logging,” describes how to configure syst em messa ge
logging. It describes the message format and how to change the message display destination device, limit
the type of message s sent , c onfigure t he U NIX ser ver sy slog daem on, and define t he U NIX syste m
logging facility and timestamp messages.
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Chapter 24, “Configuring SNMP,” describes how to configure the Simp le Networ k Ma nage ment
Protocol (SNMP). It describes how to configure community strings, enable trap managers and traps, set
the agent contact and location information, and how to limit TFTP servers used through SNMP.
Catalyst 2950 Desktop Switch Software Configuration Guide
xxvii
Conventions
Chapter 25, “Configuring Network Security with ACLs,” describes how to configure network security
by using access control list s ( ACLs).
Chapter 26, “Configuring QoS,” describes how to configure quality of service (QoS) on your switch.
With this feature, you can provide pre ferent ial tre atmen t to certa in types t raffic.
Chapter 27, “Configur ing Ether Chann els,” describes how to bundle a set of individual ports into a single
logical link on the interfaces.
Chapter 28, “Troubleshooting,” describes how to identify and resolve software problems related to the
IOS software.
Appendix A, “Supported MIBs,” lists the supported MIBs for this release and how to use FTP to access
the MIB files.
Conventions
This guide uses these conventions to convey instructions and information:
Command descriptions use these conventions:
Preface
• Commands and keywords are in boldface text.
• Arguments for which you supply values are in italic.
• Square brackets ([ ]) indicate optional elements.
• Braces ({ }) group required choices, and vertical bars ( | ) separate the alternative elements.
• Braces and vertical bars wi thin square b rackets ([{ | }] ) indicate a requir ed choice within an o ptional
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 tips 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.
xxviii
Tip Means the following will help you solve a problem. The tips information might not be troubleshootin g
or even an action, but cou ld b e use ful i nfo rmat ion.
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Preface
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/cat2950/index.htm
You can order printed copies of documents with a D OC-xxxxxx= number from the Cisco.com sites and
from the telephone numbers listed in the “Obtaining Docu me nta tio n” section on page xxix.
• Release Notes for the Catalyst 2950 Switch (not orderable but is available on Cisco.com)
• Release Notes for the Catalyst 2900 Series and Catalyst 3500 Series XL Switches (not orderable but
is available on Cisco.com)
Note Switch requirements and procedures for initial configurations and software upgrades tend to change and
therefore appear only in the release note s . Before installing, configuring, or upgrading the switch, refer
to the release notes on Cisco.com for the latest information.
• Catalyst 2950 D esktop Sw itch Comm and Refe rence (or der n um ber D OC -781 1381 =)
Related Publications
• Catalyst 2950 Desktop Switch System Message Guide (order num ber DOC-781 4233= )
• Catalyst 2950 Desktop Switch Hardware Installation Guide (order number DOC-7811157=)
• Catalyst GigaStack Gigabit Interface Converter Hardware Installation Guide
(order number DOC-786460=)
• CWDM Passive Optical System Installation Note (not orderable but is available on Cisco.com)
• 1000BASE-T GBIC Installation Notes (not or derable but is available on Cisco.c om)
• Cisco LRE CPE Hardware Installation Guide (order numbe r DOC-7811469=)
• Installation Notes for the Cisco LRE 48 POTS Splitter (not orderable but is available on Cisco.com)
• Release Notes for the Cat alyst 2950 Desk top Switch, 12. 1(11) YJ (not orde rable but is available on
Cisco.com)
Obtaining Documentation
These sections explain how to obtain docu mentation from Cisco Syste ms.
World Wide Web
You can access t he m ost c ur rent C isc o doc um ent ation on the World Wide Web at this URL :
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http://www.cisco.com
Translated documentation is available at this URL:
http://www.cisco.com/public/countries_languages.shtml
Catalyst 2950 Desktop Switch Software Configuration Guide
xxix
Obtaining Technical As sistance
Documentation CD-ROM
Cisco documentation and additional literature are available in a Cisco Documentation CD-ROM
package, which is shipped with your product. The Documentation CD-ROM is updated monthly and may
be more current than printed documentation. The CD-ROM package is available as a single unit or
through an annual subscription.
Ordering Documentation
You can order Cisco documen tation in th ese ways:
• Registered Cisco.com users (Cisco direct customers) can order Cisco product documentation from
the Networking Produ cts Market Pla ce:
http://www.cisco.com/cgi-bin/order/order_root.pl
• Registered Cisco.com users can order the Documentation CD-ROM through the online Subscription
Store:
http://www.cisco.com/go/subscription
Preface
• Nonregistered Cisco.co m u ser s can o rd er docum en tati on th rou gh a l oc al ac count r epre sen tative by
calling Cisco Systems Corpo rate Headqu arter s (Califo rnia, U.S.A. ) at 408 526-7208 or, elsewhere
in North America, by calli ng 800 55 3-NE TS (6387).
Documentation Feedback
If you are reading Cisco product documentation on the World Wide W eb, you can send us your comments
by completing the online survey. When you display the document listing fo r this platfor m, cli ck Give
Us Your Feedback. After you display the survey , select the manual that you wish to comment on. Click
Submit to send your comments to the Cisc o document ation gro up.
You can e-mail your comm ents t o bug-doc@c isco.co m.
To submit you r co mme nts by ma il, u se th e r esponse ca rd behi nd the fro nt c over of your d oc um ent, o r
write to the following address:
Cisco Systems
Attn: Document Resour ce Connec tion
170 West Tasman Drive
San Jose, CA 95134- 988 3
We apprec iate yo ur comm en ts.
Obtaining Technical Assistanc e
xxx
Cisco provides Cisco.com as a starting point for all technical assistance. Customers and partners can
obtain online documentation, troubleshooting tips, and sample configurations from online tools by using
the Cisco Technical Assistance Center (TAC) Web Site. Cisco.com registered users have complete
access to the technical support resources on the Cisco TAC Web Site.
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