Cisco 2950 - Catalyst Switch User manual

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Catalyst 2950 Desktop Switch Software
Configuration Guide
Cisco IOS Release 12.1(9)EA1
April 2002
Customer Order Number: DOC-7811380=
Text Part Number: 78-11380-04

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Catalyst 2950 Desktop Switch Software Configuration Guide
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CONTENTS
Preface xxi
Audience xxi
Purpose xxi
Organization xxii
Conventions xxiv
Related Publications xxv
Obtaining Documentation xxv
World Wide Web xxv
Documentation CD-ROM xxv
Ordering Documentation xxvi
Documentation Feedback xxvi
Obtaining Technical Assistance xxvi
Cisco.com xxvi
Technical Assistance Center xxvii
Cisco TAC Website xxvii
Cisco TAC Escalation Center xxviii
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
Multidwelling Network Using Catalyst 2950 Switches 1-14
Long-Distance, High-Bandwidth Transport Configuration 1-16
CHAPTER 2Using the Command-Line Interface 2-1
IOS Command Modes 2-1
Getting Help 2-3

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Abbreviating Commands 2-3
Using no and default Forms ofCommands 2-4
Understanding CLI Messages 2-4
Using Command History 2-5
Changing the Command History Buffer Size 2-5
Recalling Commands 2-5
Disabling the Command History Feature 2-5
Using Editing Features 2-6
Enabling and Disabling Editing Features 2-6
Editing Commands through Keystrokes 2-6
Editing Command Lines that Wrap 2-7
Searching and Filtering Output of show and more Commands 2-8
Accessing the CLI 2-9
Accessing the CLI from a Browser 2-9
Saving Configuration Changes 2-10
Where to Go Next 2-10
CHAPTER 3Getting Started with CMS 3-1
Features 3-2
Front Panel View 3-4
Cluster Tree 3-5
Front-PanelImages 3-6
Redundant Power System LED 3-7
Port Modes and LEDs 3-8
VLAN Membership Modes 3-9
Topology View 3-9
Topology Icons 3-11
Device and Link Labels 3-12
Colors in the Topology View 3-13
Topology Display Options 3-13
Menus and Toolbar 3-14
Menu Bar 3-14
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 3-25
ToolTips 3-26
Online Help 3-26
CMS Window Components 3-27
Host Name List 3-27
Tabs, Lists, and Tables 3-28
Icons Used in Windows 3-28
Buttons 3-28
Accessing CMS 3-29
Access Modes in CMS 3-30
HTTP Access to CMS 3-30
Verifying Your Changes 3-31
Change Notification 3-31
Error Checking 3-31
Saving Your Changes 3-31
UsingDifferent Versions of CMS 3-32
Where to Go Next 3-32
CHAPTER 4Assigning 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 4-3
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
Example Configuration 4-8
Manually Assigning IP Information 4-10
Checking and Saving the Running Configuration 4-11

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CHAPTER 5Configuring IE2100 CNS Agents 5-1
Understanding IE2100 Series Configuration Registrar Software 5-1
CNS Configuration Service 5-2
CNS Event Service 5-3
NameSpace Mapper 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 (Partial) Configuration 5-6
Synchronized Configuration 5-6
Configuring CNS Embedded Agents 5-6
Enabling Automated 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
Displaying CNS Configuration 5-12
CHAPTER 6Clustering 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 through CDP Hops 6-6
Discovery through Non-CDP-Capable and Noncluster-Capable Devices 6-8
Discovery through the Same Management VLAN 6-9
Discovery through Different Management VLANs 6-10
Discovery of Newly Installed Switches 6-12
HSRP and Standby Command Switches 6-14
Virtual IP Addresses 6-15
Other Considerations for Cluster Standby Groups 6-15
Automatic Recovery of Cluster Configuration 6-17

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IP Addresses 6-17
Host Names 6-18
Passwords 6-18
SNMP Community Strings 6-18
TACACS+ and RADIUS 6-19
Access Modes in CMS 6-19
ManagementVLAN 6-20
LRE Profiles 6-20
Availability of Switch-Specific Features in Switch Clusters 6-21
Creating a Switch Cluster 6-21
Enabling a Command Switch 6-22
Adding Member Switches 6-23
Creating a Cluster Standby Group 6-25
Verifying a Switch Cluster 6-27
Using the CLI to Manage Switch Clusters 6-28
Catalyst 1900 and Catalyst 2820 CLI Considerations 6-28
Using SNMP to Manage Switch Clusters 6-29
CHAPTER 7Administering the Switch 7-1
Preventing Unauthorized Access to Your Switch 7-1
Protecting Access to Privileged EXEC Commands 7-2
Default Password and Privilege Level Configuration 7-3
Setting or Changing a Static Enable Password 7-3
Protecting Enable and Enable Secret Passwords with Encryption 7-4
Setting a Telnet Password for a Terminal Line 7-5
Configuring Username and Password Pairs 7-6
Configuring Multiple Privilege Levels 7-7
Setting the Privilege Level for a Command 7-7
Changing the Default Privilege Level for Lines 7-8
Logging into and Exiting a Privilege Level 7-9
Controlling Switch Access with TACACS+ 7-9
Understanding TACACS+ 7-9
TACACS+ Operation 7-11
Configuring TACACS+ 7-12
Default TACACS+ Configuration 7-12
Identifying the TACACS+ Server Host and Setting the Authentication Key 7-12
Configuring TACACS+ Login Authentication 7-13
Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services 7-15
Starting TACACS+ Accounting 7-16

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Displaying the TACACS+ Configuration 7-16
Controlling Switch Access with RADIUS 7-17
Understanding RADIUS 7-17
RADIUS Operation 7-18
Configuring RADIUS 7-19
Default RADIUS Configuration 7-19
Identifying the RADIUS Server Host 7-20
Configuring RADIUS Login Authentication 7-22
Defining AAA Server Groups 7-24
Configuring RADIUS Authorization for Privileged EXEC Access and Network Services 7-26
Starting RADIUS Accounting 7-27
Configuring Settings for All RADIUS Servers 7-28
Configuring the Switch to Use Vendor-Specific RADIUS Attributes 7-28
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication 7-29
Displaying the RADIUS Configuration 7-30
Configuring the Switch for Local Authentication and Authorization 7-31
Configuring the Switch for Secure Shell 7-32
Understanding SSH 7-32
Configuring SSH 7-32
Managing the System Time and Date 7-33
Understanding the System Clock 7-33
Understanding Network Time Protocol 7-33
Configuring NTP 7-35
Default NTP Configuration 7-36
Configuring NTP Authentication 7-36
Configuring NTP Associations 7-37
Configuring NTP Broadcast Service 7-38
Configuring NTP Access Restrictions 7-39
Configuring the Source IP Address for NTP Packets 7-41
Displaying the NTP Configuration 7-42
Configuring Time and Date Manually 7-42
Setting the System Clock 7-43
Displaying the Time and Date Configuration 7-43
Configuring the TimeZone 7-44
Configuring Summer Time (Daylight Saving Time) 7-45
Configuring a System Nameand Prompt 7-47
Default System Name and Prompt Configuration 7-47
Configuring a System Name 7-47
Configuring a System Prompt 7-48

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Understanding DNS 7-48
Default DNS Configuration 7-49
Setting Up DNS 7-49
Displaying the DNS Configuration 7-50
Creating a Banner 7-50
Default BannerConfiguration 7-50
Configuring a Message-of-the-Day Login Banner 7-50
Configuring a Login Banner 7-52
Managing the MAC Address Table 7-52
Building the Address Table 7-53
MAC Addresses and VLANs 7-53
Default MAC Address Table Configuration 7-54
Changing the Address Aging Time 7-54
Removing Dynamic Address Entries 7-55
Configuring MAC AddressNotification Traps 7-55
Adding and Removing Static Address Entries 7-57
Configuring Static Addresses for EtherChannel Port Groups 7-58
Adding and Removing Secure Addresses 7-58
Displaying Address Table Entries 7-59
Managing the ARP Table 7-59
CHAPTER 8Configuring 802.1X Port-Based Authentication 8-1
Understanding 802.1X Port-Based Authentication 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 8-6
Default 802.1X Configuration 8-6
802.1X Configuration Guidelines 8-7
Enabling 802.1X Authentication 8-8
Configuring the Switch-to-RADIUS-ServerCommunication 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
Changing the Switch-to-Client Retransmission Time 8-12
Setting the Switch-to-Client Frame-Retransmission Number 8-13
Enabling Multiple Hosts 8-13

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Resetting the 802.1X Configuration to the Default Values 8-14
Displaying 802.1X Statisticsand Status 8-14
CHAPTER 9Configuring Interface Characteristics 9-1
Understanding Interface Types 9-1
Port-Based VLANs 9-1
Switch Ports 9-2
Access Ports 9-2
Trunk Ports 9-2
EtherChannelPort Groups 9-3
Connecting Interfaces 9-3
Using the Interface Command 9-4
Procedures for Configuring Interfaces 9-5
Configuring a Range of Interfaces 9-7
Configuring and Using Interface Range Macros 9-9
Configuring Layer 2 Interfaces 9-10
Default Layer 2 EthernetInterface Configuration 9-11
Configuring the Port Speed and Duplex Mode 9-11
Configuration Guidelines 9-12
Connecting to Devices That Do Not Autonegotiate 9-12
Setting Speed and Duplex Parameters 9-12
Configuring IEEE 802.3X Flow Control on Gigabit Ethernet Ports 9-14
Adding a Description foran Interface 9-15
Monitoring and Maintaining the Interface 9-16
Monitoring Interface and ControllerStatus 9-16
Clearing and Resetting Interfaces and Counters 9-18
Shutting Down and Restarting the Interface 9-19
CHAPTER 10 Configuring STP 10-1
Understanding Spanning-Tree Features 10-1
STP Overview 10-2
Supported Spanning-Tree Instances 10-2
Bridge ProtocolData Units 10-2
Election of the Root Switch 10-3
Bridge ID, Switch Priority, and Extended System ID 10-4
Spanning-Tree Timers 10-4
Creating the Spanning-Tree Topology 10-5