Cisco WS-C2950-24 User Manual

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Catalyst 2900 Series XL and
Catalyst 3500 Series XL
Software Configuration Guide
Cisco IOS Release 12.0(5)WC(1)
April 2001
Customer Order Number: DOC-786511=
Text Part Number: 78-6511-05

Cisco WS-C2950-24 Specifications

General

Model	WS-C2950-24
Category	Switch
Switching Capacity	8.8 Gbps
Forwarding Rate	6.6 Mpps
MAC Address Table Size	8192 entries
RAM	16 MB
Flash Memory	8 MB
Authentication Method	RADIUS, TACACS+
Manageable	Yes
Width	17.5 in
Power Supply	AC
Operating Temperature	32 to 113 °F
Operating Humidity	10 to 85% (non-condensing)
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.3x
Remote Management Protocol	SNMP, HTTP, Telnet
Height	1.75 in
Ports	24 x 10/100
Uplink Ports	2 x 10/100/1000Base-T

Summary

Preface

Audience

Defines the target reader for the guide, assuming familiarity with Ethernet and LAN concepts.

Purpose

Outlines the guide's objectives: configuring and troubleshooting switches/clusters, and LRE CPE.

Organization

Explains the structure and chapter breakdown of the manual for easy navigation.

Conventions

Details the typographical and symbolic conventions used for instructions and information.

Related Publications

Lists other relevant Cisco documentation, including release notes and command references.

Obtaining Documentation

Provides sources for acquiring Cisco documentation via World Wide Web and CD-ROM.

Ordering Documentation

Explains how to order printed copies of Cisco documentation through various channels.

Documentation Feedback

Describes methods for submitting feedback on the documentation via online surveys or email.

Obtaining Technical Assistance

Outlines how to get technical support from Cisco, including Cisco.com and TAC.

CHAPTER 1 Overview

Features

Details the software features supported in this release and related equipment.

Management Options

Discusses various interface options for managing switches and clusters.

Network Configuration Examples

Presents network configuration concepts and examples using the switches.

CHAPTER 2 Getting Started with CMS

Features

Describes the Java-based applications within CMS for managing switches.

Cluster Manager and VSM

Explains Cluster Manager and VSM applications for switch configuration and monitoring.

Cluster Tree

Details the cluster tree structure in Cluster Manager and its icon meanings.

Switch Images

Explains the use of front-panel images for visual switch management in CMS.

System LED

Describes the function and status of the system LED on the switch.

Redundant Power System LED

Explains the status indicated by the Redundant Power System (RPS) LED.

Port Modes and LEDs

Details how port modes determine the information displayed by port LEDs.

Menu Bars

Describes the VSM and Cluster Manager menu bar options and their tasks.

Toolbar

Explains the buttons on the VSM and Cluster Manager toolbars for accessing windows.

Port Pop-Up Menu

Describes the port pop-up menu for configuring switch ports.

Device Pop-Up Menu

Details the device pop-up menu for configuration and monitoring windows.

Cluster View and Cluster Builder

Introduces CMS applications for displaying, creating, and modifying switch clusters.

Topology

Explains how the topology view displays connected clusters, switches, and edge devices.

Menu Bar

Describes the menu bar options for configuring and monitoring switch clusters.

Toolbar

Explains the toolbar buttons for cluster configuration windows and online help.

Device Pop-Up Menu

Details the device pop-up menu available in Cluster View.

Candidate, Member, and Link Pop-Up Menus

Describes pop-up menu options for candidate, member, and link information in Cluster Builder.

CMS Window Components

Illustrates and explains the components of a typical CMS window.

Host Name List

Describes the Host Name drop-down list for managing cluster member names.

Tabs

Explains the use of tabs in CMS windows for organizing information.

Lists

Details how to change information by selecting items from lists in CMS.

Buttons

Describes common buttons used to change information within CMS windows.

Online Help

Explains how to access and use the comprehensive online help system in CMS.

Accessing CMS

Provides steps and prerequisites for accessing the Cluster Management Suite (CMS).

CHAPTER 3 Getting Started with the CLI

Command Usage Basics

Covers fundamental aspects of using Cisco IOS CLI commands.

Command-Line Error Messages

Lists common CLI error messages and how to get help.

Accessing the CLI

Provides procedures for accessing the Command Line Interface (CLI) via console or Telnet.

Accessing the CLI from a Browser

Explains how to access the CLI using a web browser.

Saving Configuration Changes

Details how to save configuration changes to Flash memory to prevent loss.

CHAPTER 4 General Switch Administration

Basic IP Connectivity to the Switch

Explains the IP information required for switch communication and management.

Switch Software Releases

Discusses updating switch software and checking current versions for compatibility.

Console Port Access

Describes how to access the switch via the console port using terminal emulation.

Telnet Access to the CLI

Provides steps to configure the switch for Telnet access to the CLI.

HTTP Access to CMS

Explains how CMS uses HTTP for switch management via a web browser.

SNMP Network Management Platforms

Discusses managing switches using SNMP-compatible platforms like HP OpenView.

Default Settings

Lists key software features, their default settings, and CLI/CMS configuration locations.

CHAPTER 5 Clustering Switches

Understanding Switch Clusters

Defines a switch cluster and its management as a single entity.

Command Switch Characteristics

Lists the requirements for a switch to function as a command switch in a cluster.

Standby Command Switch Characteristics

Outlines the requirements for a switch to serve as a standby command switch.

Candidate and Cluster Member Characteristics

Details the requirements for switches to be added as cluster candidates or members.

Planning a Switch Cluster

Covers considerations, requirements, and caveats for managing switch clusters.

Automatic Discovery of Cluster Candidates

Explains how CDP is used to discover and display candidate switches for clustering.

Standby Command Switches

Recommends and explains configuring standby command switches for redundancy.

IP Addresses

Discusses IP address assignment for switches in clusters to conserve IP addresses.

Passwords

Explains password assignment and privilege levels for command and member switches.

Host Names

Describes how host names are assigned and managed within a cluster.

SNMP Community Strings

Explains how SNMP community strings are propagated to member switches.

Management VLAN

Details the role of the management VLAN for switch cluster communication.

Network Port

Explains the function of network ports in relation to cluster members.

NAT Commands

Notes that NAT commands are added to the command switch configuration.

LRE Profiles

Discusses configuration conflicts related to LRE switches and profile usage.

Availability of Switch-Specific Features in Switch Clusters

Explains how switch-specific features are displayed and accessed in CMS within a cluster.

Creating a Switch Cluster

Outlines the tasks required to create a switch cluster.

Designating and Enabling a Command Switch

Provides procedures for enabling a switch as a command switch.

Adding and Removing Cluster Members

Explains how to add and remove switches from a cluster.

Designating and Enabling Standby Command Switches

Guides on creating a standby group for command switch redundancy.

Verifying a Switch Cluster

Details methods for verifying the built switch cluster and its components.

Displaying an Inventory of the Clustered Switches

Explains how to display an inventory of cluster members' information.

Displaying Link Information

Describes how to view interconnection details between cluster members.

Using the CLI to Manage Switch Clusters

Explains how to manage member switches using the CLI via the command switch.

Using SNMP to Manage Switch Clusters

Discusses managing cluster switches using SNMP applications.

CHAPTER 6 Configuring the System

Changing IP Information

Covers assigning and changing switch IP information using various methods.

Manually Assigning and Removing Switch IP Information

Details the procedure for manually setting or clearing switch IP addresses.

Using DHCP-Based Autoconfiguration

Explains how DHCP enables automatic IP configuration for the switch.

Understanding DHCP-Based Autoconfiguration

Describes the DHCP client-server model for automatic switch configuration.

DHCP Client Request Process

Illustrates the message sequence between DHCP client and server for IP information.

Configuring the DHCP Server

Provides guidelines for configuring DHCP servers with lease options for switches.

Configuring the TFTP Server

Explains the requirements for setting up a TFTP server with configuration files.

Configuring the Domain Name and the DNS

Covers configuring domain names and enabling the Domain Name System (DNS).

Configuring the Relay Device

Details how to configure relay devices for DHCP, DNS, and TFTP server access.

Obtaining Configuration Files

Explains how the switch obtains configuration files based on DHCP replies.

Example Configuration

Presents a sample network for DHCP-based autoconfiguration.

Changing the Password

Covers assigning and changing passwords to protect switch access and configuration.

Setting the System Date and Time

Explains how to set the switch's date, time, and time zone.

Configuring Daylight Saving Time

Details how to configure the switch for daylight saving time adjustments.

Configuring the Network Time Protocol

Discusses using NTP to distribute time information from a central server.

Configuring the Switch as an NTP Client

Guides on configuring the switch to act as an NTP client for time synchronization.

Enabling NTP Authentication

Explains how to authenticate NTP messages for information validity.

Configuring the Switch for NTP Broadcast-Client Mode

Covers configuring the switch to receive NTP broadcast messages.

Configuring SNMP

Discusses configuring SNMP parameters and the impact of clustering.

Disabling and Enabling SNMP

Explains the default SNMP status and its necessity for cluster management.

Entering Community Strings

Details how to enter community strings for SNMP messages and cluster members.

Adding Trap Managers

Explains how to configure trap managers to receive SNMP traps.

Configuring CDP

Covers enabling CDP, setting parameters, and displaying neighboring device information.

Configuring CDP for Extended Discovery

Explains how to change CDP settings to discover devices further away.

Configuring STP

Discusses Spanning Tree Protocol (STP) for path redundancy and loop prevention.

Supported STP Instances

Explains how STP instances are created and managed per VLAN.

Using STP to Support Redundant Connectivity

Details using STP to create redundant backbones and links.

Disabling STP

Guides on disabling STP, emphasizing caution regarding network loops.

Accelerating Aging to Retain Connectivity

Explains how aging time is accelerated to retain connectivity during STP reconfigurations.

Configuring STP and UplinkFast in a Cascaded Cluster

Discusses reducing STP default values for cascaded configurations.

Configuring Redundant Links By Using STP UplinkFast

Explains using STP UplinkFast to manage redundant links.

Enabling STP UplinkFast

Guides on enabling the UplinkFast feature for the entire switch.

Configuring Cross-Stack UplinkFast

Details Cross-Stack UplinkFast (CSUF) for fast spanning-tree transitions in stacks.

How CSUF Works

Explains the mechanism of CSUF in ensuring a path to the root.

Events that Cause Fast Convergence

Lists network events that can trigger fast convergence with CSUF.

Limitations

Outlines the limitations associated with the CSUF feature.

Connecting the Stack Ports

Provides guidelines for connecting stack ports for fast transitions.

Changing the STP Parameters for a VLAN

Explains how to change root parameters for VLANs to affect STP responses.

Changing the STP Implementation

Guides on changing the STP implementation method (IBM or IEEE).

Changing the Switch Priority

Details how to change switch priority to influence the root switch selection.

Changing the BPDU Message Interval

Explains how to change the BPDU message interval (max age time).

Changing the Hello BPDU Interval

Guides on changing the hello BPDU interval (hello time).

Changing the Forwarding Delay Time

Details how to change the forwarding delay time for STP.

STP Port States

Describes the different states a port can be in due to STP.

Enabling the Port Fast Feature

Explains how Port Fast brings a port quickly to the STP forwarding state.

Changing the Path Cost

Details how to change the path cost for STP calculations.

Changing the Port Priority

Guides on changing port priority for root switch tie-breaking.

Configuring STP Root Guard

Explains how to configure root guard to prevent customer switches from becoming the root.

Managing the ARP Table

Covers managing the Address Resolution Protocol (ARP) table for MAC address resolution.

Controlling IP Multicast Packets through CGMP

Discusses CGMP for reducing unnecessary flooding of IP multicast packets.

Enabling the Fast Leave Feature

Explains how the CGMP Fast Leave feature reduces delay when group members leave.

Disabling the CGMP Fast Leave Feature

Guides on disabling the CGMP Fast Leave feature.

Changing the CGMP Router Hold-Time

Details how to change the router hold-time for CGMP.

Removing Multicast Groups

Explains how to reduce IP multicast packet forwarding by removing groups.

Configuring MVR

Describes Multicast VLAN Registration (MVR) for wide-scale multicast traffic deployment.

Using MVR in a Multicast Television Application

Illustrates using MVR in a multicast television application scenario.

Configuration Guidelines and Limitations

Provides guidelines and limitations for configuring MVR.

Setting MVR Parameters

Guides on setting MVR parameters, including multicast VLAN.

Configuring MVR

Details the steps for configuring MVR on the switch.

Managing the MAC Address Tables

Covers managing MAC address tables used for traffic forwarding.

MAC Addresses and VLANs

Explains how MAC addresses are associated with VLANs and their destinations.

Changing the Address Aging Time

Details how to configure the dynamic address table aging time.

Removing Dynamic Address Entries

Guides on removing dynamic address entries from the MAC table.

Adding Secure Addresses

Explains how to add secure MAC addresses and their associated ports.

Removing Secure Addresses

Guides on removing secure addresses from the MAC table.

Adding Static Addresses

Covers adding static MAC addresses, including port and VLAN assignments.

Removing Static Addresses

Guides on removing static MAC addresses from the table.

Configuring Static Addresses for EtherChannel Port Groups

Provides rules for configuring static addresses for EtherChannel port groups.

Configuring TACACS+

Explains TACACS+ for managing network security via AAA from a server.

Configuring the TACACS+ Server Host

Details specifying IP host names for AAA/TACACS+ servers.

Configuring Login Authentication

Guides on configuring login authentication using AAA/TACACS+.

Specifying TACACS+ Authorization for EXEC Access and Network Services

Covers setting parameters to restrict user network access via TACACS+.

Starting TACACS+ Accounting

Explains how to enable TACACS+ accounting for privilege levels and network services.

Configuring a Switch for Local AAA

Guides on configuring AAA in local mode without a server for authentication.

CHAPTER 7 Configuring the Switch Ports

Changing the Port Speed and Duplex Mode

Discusses changing port speed and duplex settings, including guidelines for autonegotiation.

Connecting to Devices That Do Not Autonegotiate

Guides on connecting devices that do not support autonegotiation.

Setting Speed and Duplex Parameters

Details setting speed and duplex parameters on a port.

Configuring Flow Control on Gigabit Ethernet Ports

Explains how to configure flow control on Gigabit Ethernet ports.

Configuring Flooding Controls

Covers flooding techniques to block unnecessary traffic.

Enabling Storm Control

Explains how storm control prevents network slowdown from excessive packets.

Disabling Storm Control

Guides on disabling broadcast-storm control.

Blocking Flooded Traffic on a Port

Details disabling flooding of multicast and unicast packets on a per-port basis.

Resuming Normal Forwarding on a Port

Guides on resuming normal forwarding on a port after blocking.

Enabling a Network Port

Explains how network ports reduce flooded traffic and handle unknown destinations.

Disabling a Network Port

Guides on disabling a port designated as a network port.

Configuring UniDirectional Link Detection

Details configuring UDLD to detect and shut down unidirectional links.

Creating EtherChannel Port Groups

Explains creating EtherChannel port groups for high-bandwidth connections.

Understanding EtherChannel Port Grouping

Describes source-based and destination-based port group types.

Port Group Restrictions on Static-Address Forwarding

Lists restrictions for static addresses forwarded to port groups.

Creating EtherChannel Port Groups

Outlines steps to create a two-port EtherChannel group.

Configuring Protected Ports

Covers configuring ports as protected to restrict Layer 2 traffic forwarding.

Enabling Port Security

Details securing ports by restricting them to user-defined stations.

Defining the Maximum Secure Address Count

Explains setting the maximum number of secure addresses for a port.

Enabling Port Security

Guides on enabling port security to restrict port access.

Disabling Port Security

Guides on disabling port security.

Enabling SPAN

Explains using Switch Port Analyzer (SPAN) to monitor traffic on a port.

Disabling SPAN

Guides on disabling SPAN port monitoring.

Configuring Voice Ports

Covers connecting to Cisco IP Phones and carrying IP voice traffic.

Preparing a Port for a Cisco 7960 IP Phone Connection

Guides on preparing a port for IP voice traffic and VLAN configuration.

Configuring a Port to Connect to a Cisco 7960 IP Phone

Details configurations for carrying mixed traffic with Cisco IP Phones.

Overriding the CoS Priority of Incoming Frames

Explains how to override or trust CoS priority for incoming frames.

Configuring Voice Ports to Carry Voice and Data Traffic on Different VLANs

Guides on configuring ports for voice and data traffic on separate VLANs.

Configuring Inline Power on the Catalyst 3524-PWR Ports

Details configuring inline power supply to Cisco IP Phones.

Configuring the LRE Ports

Explains using Long-Reach Ethernet (LRE) technology for data and voice traffic.

LRE Links and LRE Profiles

Details LRE link settings and profile configurations for performance.

LRE Ethernet Links

Covers Ethernet link settings for remote CPE connections on LRE ports.

Assigning a Public Profile to All LRE Ports

Guides on assigning public profiles to LRE ports for PSTN compatibility.

Assigning a Private Profile to an LRE Port

Details assigning private profiles to LRE ports on a per-port basis.

CHAPTER 8 Configuring VLANs

Overview

Defines Virtual LAN (VLAN) as a logical network segmentation method.

Maximum Number of Supported VLANs

Lists the number of supported VLANs and trunking capabilities per switch model.

Management VLANs

Discusses the role and characteristics of the management VLAN for switch communication.

Changing the Management VLAN for a New Switch

Guides on automatically changing the management VLAN for new switches in a cluster.

Changing the Management VLAN Through a Telnet Connection

Details configuring the management VLAN interface via a Telnet connection.

Assigning VLAN Port Membership Modes

Explains how to assign port membership modes to define traffic types and VLAN belonging.

VLAN Membership Combinations

Lists various VLAN membership combinations for switch ports.

Assigning Static-Access Ports to a VLAN

Guides on assigning static-access ports to VLANs, including multi-VLAN configuration.

Overlapping VLANs and Multi-VLAN Ports

Discusses how multi-VLAN ports link multiple VLANs to a router.

Using VTP

Explains VLAN Trunk Protocol (VTP) for maintaining VLAN configuration consistency.

The VTP Domain

Defines a VTP domain and its administrative responsibility for VLAN management.

VTP Modes and Mode Transitions

Describes VTP modes (Server, Client, Transparent) and their transitions.

VTP Advertisements

Explains global configuration advertisements sent between switches in a VTP domain.

VTP Version 2

Details features supported by VTP version 2, including Token Ring support.

Disabling VTP (VTP Transparent Mode)

Guides on disabling VTP by configuring the switch in transparent mode.

Enabling VTP Version 2

Explains enabling VTP version 2, noting interoperability caveats.

Disabling VTP Version 2

Guides on disabling VTP version 2.

Enabling VTP Pruning

Discusses enabling VTP pruning to increase bandwidth by restricting flooded traffic.

Monitoring VTP

Explains how to monitor VTP configuration and statistics.

VLANs in the VTP Database

Lists parameters that can be set when adding or modifying VLANs in the VTP database.

Token Ring VLANs

Mentions Token Ring VLAN support via remote devices and VTP version 2.

VLAN Configuration Guidelines

Provides guidelines for creating and modifying VLANs in a network.

Default VLAN Configuration

Lists default configurations and ranges for various VLAN media types.

Configuring VLANs in the VTP Database

Details using CLI commands to add, change, and delete VLANs in the VTP database.

Adding a VLAN

Guides on adding an Ethernet VLAN by assigning a number and name.

Modifying a VLAN

Details modifying an Ethernet VLAN, including changing the MTU size.

Deleting a VLAN from the Database

Explains how to delete a VLAN from the VTP database, noting restrictions.

Assigning Static-Access Ports to a VLAN

Guides on assigning ports to VLANs, including multi-VLAN membership.

How VLAN Trunks Work

Explains VLAN trunks as point-to-point links for carrying multiple VLAN traffic.

IEEE 802.1Q Configuration Considerations

Lists restrictions and considerations for using IEEE 802.1Q trunks.

Trunks Interacting with Other Features

Describes how trunking interacts with other switch features.

Configuring a Trunk Port

Guides on configuring a port as an ISL or 802.1Q trunk port.

Disabling a Trunk Port

Explains how to disable trunking on a port by returning it to static-access mode.

Defining the Allowed VLANs on a Trunk

Details how to remove VLANs from the allowed list on a trunk port to restrict traffic.

Changing the Pruning-Eligible List

Guides on removing VLANs from the pruning-eligible list on trunk ports.

Configuring the Native VLAN for Untagged Traffic

Explains how to configure the native VLAN for handling untagged traffic on 802.1Q trunks.

Configuring 802.1p Class of Service

Covers Quality of Service (QoS) based on IEEE 802.1p class of service values.

How Class of Service Works

Explains how Class of Service (CoS) classifies frames for priority transmission.

Port Priority

Describes how frames are classified and tagged for transmission based on priority.

Port Scheduling

Explains the transmit queues and priority levels for switch ports.

Configuring the CoS Port Priorities

Guides on setting port priority for untagged Ethernet frames.

Load Sharing Using STP

Discusses dividing bandwidth supplied by parallel trunks using STP.

Load Sharing Using STP Port Priorities

Explains load sharing by setting STP port priorities on trunk ports.

Configuring STP Port Priorities and Load Sharing

Guides on configuring STP port priorities and load sharing for network traffic distribution.

Load Sharing Using STP Path Cost

Explains configuring parallel trunks to share VLAN traffic by setting different path costs.

How the VMPS Works

Describes the VLAN Membership Policy Server (VMPS) client-server communication.

Dynamic Port VLAN Membership

Explains how dynamic ports learn VLAN assignments from VMPS.

VMPS Database Configuration File

Details the VMPS database configuration file stored on a TFTP server.

VMPS Configuration Guidelines

Provides guidelines and restrictions for dynamic port VLAN membership.

Default VMPS Configuration

Lists the default VMPS and dynamic port configuration on client switches.

Configuring Dynamic VLAN Membership

Guides on entering the IP address of the VMPS to configure switches as clients.

Configuring Dynamic Ports on VMPS Clients

Details configuring dynamic ports on VMPS client switches for end stations.

Reconfirming VLAN Memberships

Explains how VMPS clients periodically reconfirm VLAN membership.

Changing the Reconfirmation Interval

Guides on setting the reconfirmation interval for VMPS clients.

Changing the Retry Count

Details changing the retry count for contacting VMPS servers.

Administering and Monitoring the VMPS

Explains how to display and monitor VMPS information using the show vmps command.

Troubleshooting Dynamic Port VLAN Membership

Addresses issues with dynamic port VLAN membership and provides solutions.

Dynamic Port VLAN Membership Configuration Example

Presents a network example of VMPS server and client configuration.

CHAPTER 9 Troubleshooting

Avoiding Configuration Conflicts

Identifies conflicting port features and provides guidance on avoiding them.

Avoiding Autonegotiation Mismatches

Discusses common autonegotiation mismatches and how to maximize switch performance.

Copying Configuration Files to Troubleshoot Configuration Problems

Explains using Flash memory to copy files for troubleshooting and backup.

Troubleshooting LRE Port Configuration

Lists common problems with Long-Reach Ethernet (LRE) ports and their suggested solutions.

Troubleshooting CMS Sessions

Addresses common problems encountered when using Cluster Management Suite (CMS).

Troubleshooting Switch Upgrades

Lists common problems encountered during switch software upgrades and their solutions.

Recovering from Corrupted Software

Provides procedures using XMODEM Protocol to recover from corrupt or wrong image files.

Recovering from a Lost or Forgotten Password

Guides on recovering lost or forgotten switch passwords via console port.

Recovery Procedures

Outlines procedures for recovering switches, including lost connectivity and failures.

APPENDIX A System Error Messages

How to Read System Error Messages

Explains the structure and components of system error messages.

Error Message Traceback Reports

Describes internal errors and includes traceback information for reporting problems.

Error Message and Recovery Procedures

Lists system messages by facility, severity, explanation, and recommended action.