Cisco 2950 - Catalyst Switch User manual

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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 2955 Switch Software Configuration Guide
Copyright © 2001–2004 Cisco Systems, Inc. All rights reserved4

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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 Support Website xxxiii
Submitting a Service Request xxxiii
Definitions of Service Request Severity xxxiii
Obtaining AdditionalPublications andInformation xxxiv
CHAPTER 1Overview 1-1
Features 1-1
ManagementOptions 1-8
ManagementInterface Options 1-8
Advantages of Using CMS and Clustering 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 Configuration 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

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CHAPTER 2Using 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 ofCommands 2-4
Understanding CLI Messages 2-5
Using Command History 2-5
Changing the Command History Buffer Size 2-5
Recalling Commands 2-6
Disabling the Command History Feature 2-6
Using Editing Features 2-6
Enabling and Disabling Editing Features 2-6
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 3Configuring Catalyst 2955 Switch Alarms 3-1
Understanding Catalyst 2955 Switch Alarms 3-1
Global Status Monitoring Alarms 3-2
FCS ErrorHysteresis Threshold 3-2
Port Status Monitoring Alarms 3-3
Triggering Alarm Options 3-3
Configuring Catalyst 2955 Switch Alarms 3-4
Default Catalyst 2955 Switch Alarm Configuration 3-4
Configuring the Power Supply Alarm 3-5
Setting the Power Mode 3-5
Setting the Power Supply Alarm Options 3-5
Configuring the Switch Temperature Alarms 3-6
Setting a Secondary Temperature Threshold for the Switch 3-6
Associating the Temperature Alarms to a Relay 3-7
Configuring the FCS Bit Error Rate Alarm 3-7
Setting the FCS Error Threshold 3-8
Setting the FCS Error Hysteresis Threshold 3-8

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Configuring Alarm Profiles 3-9
Creating or Modifying an Alarm Profile 3-9
Attaching an Alarm Profile to a Specific Port 3-10
Enabling SNMP Traps 3-11
Displaying Catalyst 2955 Switch Alarms Status 3-11
CHAPTER 4Getting Started with CMS 4-1
Understanding CMS 4-1
Front Panel View 4-1
Topology View 4-2
CMS Menu Bar, Toolbar, and Feature Bar 4-2
Online Help 4-5
Configuration Modes 4-5
Guide Mode 4-5
Expert Mode 4-6
Wizards 4-6
Privilege Levels 4-7
Access to Older Switches in a Cluster 4-7
Configuring CMS 4-7
CMS Requirements 4-8
Minimum Hardware Configuration 4-8
Operating System and BrowserSupport 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

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CHAPTER 5Assigning the Switch IP Address and DefaultGateway 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 ServerConfiguration 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 Startup Configuration 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 Scheduled Reload Information 5-17
CHAPTER 6Configuring IE2100 CNS Agents 6-1
Understanding IE2100 Series Configuration Registrar Software 6-1
CNS Configuration Service 6-2
CNS Event Service 6-3
NameSpace Mapper 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

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Understanding CNS Embedded Agents 6-5
Initial Configuration 6-5
Incremental (Partial) Configuration 6-6
Synchronized Configuration 6-6
Configuring CNS Embedded Agents 6-6
Enabling Automated CNS Configuration 6-6
Enabling the CNS Event 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 7Clustering 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 Switch Cluster 7-5
Automatic Discovery of Cluster Candidates and Members 7-5
Discovery through CDP Hops 7-6
Discovery through Non-CDP-Capable and Noncluster-Capable Devices 7-7
Discovery through the Same Management VLAN 7-8
Discovery through Different Management VLANs 7-9
Discovery of Newly Installed Switches 7-10
HSRP and Standby Command Switches 7-11
Virtual IP Addresses 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
ManagementVLAN 7-16
LRE Profiles 7-17
Availability of Switch-Specific Features in Switch Clusters 7-17

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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 Cluster 7-22
Using the CLI to Manage Switch Clusters 7-23
Catalyst 1900 and Catalyst 2820 CLI Considerations 7-24
Using SNMP to Manage Switch Clusters 7-24
CHAPTER 8Administering 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 Configuration 8-4
Configuring NTP Authentication 8-4
Configuring NTP Associations 8-6
Configuring NTP Broadcast Service 8-7
Configuring NTP Access Restrictions 8-8
Configuring the Source IP Address for NTP Packets 8-10
Displaying the NTP Configuration 8-11
Configuring Time and Date Manually 8-11
Setting the System Clock 8-12
Displaying the Time and Date Configuration 8-12
Configuring the TimeZone 8-13
Configuring Summer Time (Daylight Saving Time) 8-14
Configuring a System Nameand 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 Configuration 8-19
Configuring a Message-of-the-Day Login Banner 8-20
Configuring a Login Banner 8-21

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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 Table Configuration 8-23
Changing the Address 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 Address Table Entries 8-28
Managing the ARP Table 8-28
CHAPTER 9Configuring 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 Username and Password Pairs 9-7
Configuring Multiple Privilege Levels 9-8
Setting the Privilege 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+ Configuration 9-13
Identifying the TACACS+ Server Host and Setting the 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 TACACS+ Configuration 9-17
Controlling Switch Access with RADIUS 9-18
Understanding RADIUS 9-18
RADIUS Operation 9-19

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Configuring RADIUS 9-20
Default RADIUS Configuration 9-20
Identifying the RADIUS Server Host 9-21
Configuring RADIUS 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 Settings 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
ConfigurationGuidelines 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 SSH Configuration and Status 9-37
CHAPTER 10 Configuring 802.1x Port-Based Authentication 10-1
Understanding 802.1x 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