Cisco 2950 - Catalyst Switch Quick start guide

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Catalyst 2950 Desktop Switch Software
Configuration Guide
Cisco IOS Release 12.1(6)EA2b
March, 2002
Customer Order Number: DOC-7811380=
Text Part Number: 78-11380-03

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Catalyst 2950 Desktop Switch Software Configuration Guide
Copyright © 2002, Cisco Systems, Inc.
All rights reserved.
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CONTENTS
Preface xvii
Audience xvii
Purpose xvii
Organization xviii
Conventions xix
Related Publications xx
Obtaining Documentation xx
World Wide Web xx
Documentation CD-ROM xxi
Ordering Documentation xxi
Documentation Feedback xxi
Obtaining Technical Assistance xxi
Cisco.com xxii
Technical Assistance Center xxii
Cisco TAC Web Site xxii
Cisco TAC Escalation Center xxiii
CHAPTER 1Overview 1-1
Features 1-1
ManagementOptions 1-6
ManagementInterface Options 1-6
Advantages of Using CMS and Clustering Switches 1-7
Network Configuration Examples 1-8
Design Concepts for Using the Switch 1-8
Small to Medium-Sized Network Configuration 1-10
Collapsed Backbone and Switch Cluster Configuration 1-12
Large Campus Configuration 1-13
CHAPTER 2Getting Started with CMS 2-1
Features 2-2
Front Panel View 2-4
Cluster Tree 2-5
Front-Panel Images 2-6
Redundant Power System LED 2-7

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Port Modes and LEDs 2-8
VLAN Membership Modes 2-9
Topology View 2-10
Topology Icons 2-12
Device and Link Labels 2-13
Colors in the Topology View 2-14
Topology Display Options 2-14
Menus and Toolbar 2-15
Menu Bar 2-15
Toolbar 2-20
Front Panel View Popup Menus 2-21
Device Popup Menu 2-21
Port Popup Menu 2-21
Topology View Popup Menus 2-22
Link Popup Menu 2-22
Device Popup Menus 2-23
Interaction Modes 2-25
Guide Mode 2-25
Expert Mode 2-25
Wizards 2-26
ToolTips 2-26
Online Help 2-27
CMS Window Components 2-28
Host Name List 2-28
Tabs, Lists, and Tables 2-29
Icons Used in Windows 2-29
Buttons 2-29
Accessing CMS 2-30
Access Modes in CMS 2-31
Verifying Your Changes 2-32
Change Notification 2-32
Error Checking 2-32
Saving Your Changes 2-32
UsingDifferent Versions of CMS 2-33
Where to Go Next 2-33

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CHAPTER 3Using the Command-Line Interface 3-1
IOS Command Modes 3-1
Getting Help 3-3
Abbreviating Commands 3-3
Using no and default Forms of Commands 3-4
Understanding CLI Messages 3-4
Using Command History 3-5
Changing the Command History Buffer Size 3-5
Recalling Commands 3-5
Disabling the Command History Feature 3-5
Using Editing Features 3-6
Enabling and Disabling Editing Features 3-6
Editing Commands through Keystrokes 3-6
Editing Command Lines that Wrap 3-7
Searching and Filtering Output of show and more Commands 3-8
Accessing the CLI 3-9
Accessing the CLI from a Browser 3-9
Saving Configuration Changes 3-10
Where to Go Next 3-10
CHAPTER 4General Switch Administration 4-1
Basic IP Connectivity to the Switch 4-1
Switch Software Releases 4-2
Console Port Access 4-2
Telnet Access to the CLI 4-2
HTTP Access to CMS 4-3
SNMP Network Management Platforms 4-4
SNMP Versions 4-4
Using FTP to Access the MIB Files 4-5
Using SNMP to Access MIB Variables 4-5
Default Settings 4-6
CHAPTER 5Clustering Switches 5-1
Understanding Switch Clusters 5-2
Command Switch Characteristics 5-2
Standby Command Switch Characteristics 5-3
Candidate and Member Switches Characteristics 5-3

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Planning a Switch Cluster 5-4
Automatic Discovery of Cluster Candidates and Members 5-4
Discovery through CDP Hops 5-5
Discovery through Non-CDP-Capable and Noncluster-Capable Devices 5-6
Discovery through the Same Management VLAN 5-7
Discovery through Different Management VLANs 5-8
Discovery of Newly Installed Switches 5-9
HSRP and Standby Command Switches 5-10
Virtual IP Addresses 5-11
Automatic Recovery of Cluster Configuration 5-11
Considerations for Cluster Standby Groups 5-12
IP Addresses 5-13
Host Names 5-14
Passwords 5-14
SNMP Community Strings 5-14
TACACS+ 5-15
Access Modes in CMS 5-15
ManagementVLAN 5-15
LRE Profiles 5-16
Availability of Switch-Specific Features in Switch Clusters 5-16
Creating a Switch Cluster 5-16
Enabling a Command Switch 5-17
Adding Member Switches 5-18
Creating a Cluster Standby Group 5-20
Verifying a Switch Cluster 5-22
Using the CLI to Manage Switch Clusters 5-23
Catalyst 1900 and Catalyst 2820 CLI Considerations 5-23
Using SNMP to Manage Switch Clusters 5-24
CHAPTER 6Configuring the System 6-1
Changing IP Information 6-1
Manually Assigning and Removing Switch IP Information 6-2
Using DHCP-Based Autoconfiguration 6-2
Understanding DHCP-Based Autoconfiguration 6-3
DHCP Client Request Process 6-3
Configuring the DHCP Server 6-4
Configuring the TFTP Server 6-5
Configuring the Domain Name and the DNS 6-5
Configuring the Relay Device 6-6

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Obtaining Configuration Files 6-7
Example Configuration 6-8
Changing the Password 6-10
Setting the System Date and Time 6-11
Configuring DaylightSaving Time 6-11
Configuring the Network Time Protocol 6-11
Configuring the Switch as an NTP Client 6-11
Enabling NTP Authentication 6-11
Configuring the Switch for NTP Broadcast-Client Mode 6-12
Configuring SNMP 6-12
Disabling and Enabling SNMP 6-12
Entering Community Strings 6-12
Adding Trap Managers 6-12
Configuring CDP 6-13
Configuring CDP for Extended Discovery 6-14
Managing the ARP Table 6-14
Managing the MAC Address Tables 6-15
MAC Addresses and VLANs 6-15
Changing the Address Aging Time 6-16
Removing Dynamic Address Entries 6-16
MAC Address Notification 6-17
Enabling Notification of Learned or Deleted MAC Addresses 6-17
Adding Secure Addresses 6-18
Removing Secure Addresses 6-18
Adding and Removing Static Address Entries 6-18
Configuring Static Addresses for EtherChannel Port Groups 6-19
Configuring TACACS+ 6-20
Configuring the TACACS+ Server Host 6-20
Configuring Login Authentication 6-21
Specifying TACACS+ Authorization for Privileged EXEC Access and Network Services 6-22
Starting TACACS+ Accounting 6-22
Configuring a Switch for Local AAA 6-23
Controlling Switch Access with RADIUS 6-24
Understanding RADIUS 6-24
RADIUS Operation 6-25
Configuring RADIUS 6-26
Default RADIUS Configuration 6-26
Identifying the RADIUS Server Host 6-27
Configuring RADIUS LoginAuthentication 6-29

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Defining AAA Server Groups 6-31
Configuring RADIUS Authorization for Privileged EXEC Access and Network Services 6-33
Starting RADIUS Accounting 6-34
Configuring Settings for All RADIUS Servers 6-35
Configuring the Switch to Use Vendor-Specific RADIUS Attributes 6-35
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 6-36
Displaying the RADIUS Configuration 6-37
CHAPTER 7Configuring 802.1X Port-Based Authentication 7-1
Understanding 802.1X Port-Based Authentication 7-1
Device Roles 7-2
Authentication Initiation and Message Exchange 7-3
Ports in Authorized and Unauthorized States 7-4
Supported Topologies 7-5
Configuring 802.1X Authentication 7-6
Default 802.1X Configuration 7-6
802.1X Configuration Guidelines 7-7
Enabling 802.1X Authentication 7-8
Configuring the Switch-to-RADIUS-Server Communication 7-9
Enabling Periodic Re-Authentication 7-10
Manually Re-Authenticating a Client Connected to aPort 7-11
Changing the Quiet Period 7-11
Changing the Switch-to-Client Retransmission Time 7-12
Setting the Switch-to-Client Frame-Retransmission Number 7-13
Enabling Multiple Hosts 7-13
Resetting the 802.1X Configuration to the Default Values 7-14
Displaying 802.1X Statistics and Status 7-14
CHAPTER 8Configuring VLANs 8-1
Overview 8-1
ManagementVLANs 8-3
Changing the Management VLAN fora New Switch 8-3
Changing the Management VLAN Through a Telnet Connection 8-4
Assigning VLAN Port Membership Modes 8-4
VLAN Membership Combinations 8-6
Assigning Static-Access Ports to a VLAN 8-7
Using VTP 8-7
The VTP Domain 8-7
VTP Modes and Mode Transitions 8-7

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VTP Advertisements 8-8
VTP Version 2 8-9
VTP Pruning 8-9
VTP Configuration Guidelines 8-10
Domain Names 8-10
Passwords 8-10
Upgrading from Previous Software Releases 8-11
VTP Version 8-11
Default VTP Configuration 8-11
Configuring VTP 8-12
Configuring VTP Server Mode 8-12
Configuring VTP ClientMode 8-12
Disabling VTP (VTP Transparent Mode) 8-13
Enabling VTP Version 2 8-14
Disabling VTP Version 2 8-14
Enabling VTP Pruning 8-15
Monitoring VTP 8-15
VLANs in the VTP Database 8-15
Token Ring VLANs 8-16
VLAN Configuration Guidelines 8-16
Default VLAN Configuration 8-16
Configuring VLANs in the VTP Database 8-17
Adding a VLAN 8-18
Modifying a VLAN 8-18
Deleting a VLAN from the Database 8-18
Assigning Static-Access Ports to a VLAN 8-19
How VLAN Trunks Work 8-20
IEEE 802.1Q Configuration Considerations 8-21
Trunks Interacting with Other Features 8-21
Configuring a Trunk Port 8-22
CLI: Disabling a Trunk Port 8-22
CLI: Defining the Allowed VLANs on a Trunk 8-23
Changing the Pruning-Eligible List 8-23
Configuring the Native VLAN for Untagged Traffic 8-24
Load Sharing Using STP 8-24
Load Sharing Using STP Port Priorities 8-25
Configuring STP PortPriorities and Load Sharing 8-25
Load Sharing Using STP Path Cost 8-27
How the VMPS Works 8-28

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Dynamic Port VLAN Membership 8-29
VMPS Database Configuration File 8-29
VMPS Configuration Guidelines 8-31
Default VMPS Configuration 8-31
Configuring Dynamic VLAN Membership 8-31
Configuring Dynamic Ports on VMPS Clients 8-32
Reconfirming VLAN Memberships 8-33
Changing the Reconfirmation Interval 8-33
Changing the Retry Count 8-33
Administering and Monitoring the VMPS 8-34
Troubleshooting Dynamic Port VLAN Membership 8-34
Dynamic Port VLAN Membership Configuration Example 8-34
CHAPTER 9Configuring STP 9-1
Understanding Basic STP Features 9-1
Supported STP Instances 9-2
STP Overview 9-2
Election of the Root Switch 9-3
Bridge Protocol Data Units 9-3
STP Timers 9-4
Creating the STP Topology 9-4
STP Interface States 9-5
Blocking State 9-6
Listening State 9-7
Learning State 9-7
Forwarding State 9-7
Disabled State 9-7
MAC Address Allocation 9-8
STP Address Management 9-8
STP and IEEE 802.1Q Trunks 9-8
STP and Redundant Connectivity 9-8
Accelerated Aging to Retain Connectivity 9-9
Understanding Advanced STP Features 9-9
Understanding Port Fast 9-10
Understanding BPDU Guard 9-10
Understanding UplinkFast 9-11
Understanding Cross-Stack UplinkFast 9-12
How CSUF Works 9-13
Events that Cause Fast Convergence 9-14