Catalyst 2950 Desktop Switch Command Reference, 12.1(11)YJ
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Related Publications

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This guide is for the networking professional using the Cisco IOS command-line interface (CLI) to manage the Catalyst 2950 switch, hereafter referred to as the switch. Before using this guide, you should have experience working with the Cisco IOS and be familiar with the concepts and terminology of Ethernet and local area networking.


The Catalyst 2950 switch is supported by either the standard software image (SI) or the enhanced software image (EI). The enhanced software image provides a richer set of features, including access control lists (ACLs), enhanced quality of service (QoS) features, the Secure Shell (SSH) Protocol, extended-range VLANs, the IEEE 802.1W Rapid Spanning Tree Protocol (STP), and the IEEE 802.1S Multiple STP.

Note This guide describes the features for all Catalyst 2950 switches, including the Catalyst 2950 Long-Reach Ethernet (LRE) switches. Cisco IOS Release 12.1(11)EA1 is not for the LRE switches. Do not install Release 12.1(11)EA1 on the Catalyst 2950 LRE switches.

Release 12.1(11)YJ is for the Catalyst 2950 LRE switches only. Do not install Release 12.1(11)YJ on non-LRE switches.

The enhanced software image supports these switches:

Catalyst 2950C-24

Catalyst 2950G-12-EI

Catalyst 2950G-24-EI 

Catalyst 2950G-24-EI-DC

Catalyst 2950G-48-EI

Catalyst 2950T-24

Catalyst 2950ST-8-LRE

Catalyst 2950ST-24-LRE

The standard software image supports these switches:

Catalyst 2950-12

Catalyst 2950-24

Catalyst 2950SX-24

This guide provides the information you need about the CLI commands that have been created or changed for use with the Catalyst 2950 family of switches. For information about the standard IOS Release 12.1 commands, refer to the IOS documentation set available from the home page by selecting Service and Support > Technical Documents. On the Cisco Product Documentation home page, select Release 12.1 from the Cisco IOS Software drop-down list.

This guide does not provide procedures for configuring your switch. For detailed configuration procedures, refer to the Catalyst 2950 Desktop Switch Software Configuration Guide for this release.

This guide does not describe system messages you might encounter. For more information, refer to the Catalyst 2950 Desktop Switch System Message Guide for this release.


This guide is organized into these chapters:

"Using the Command-Line Interface," describes how to access the command modes and use the switch CLI to configure software features. It also lists the commands that have the same function but different syntax in software releases earlier than Release 12.1(6)EA2 and in Release 12.1(6)EA2 or later.

"Cisco IOS Commands," describes in alphabetical order the IOS commands that you use to configure and monitor your switch.

"Debug Commands," describes the debug privileged EXEC commands. Debug commands are helpful in diagnosing and resolving internetworking problems.


This guide uses these conventions to convey instructions and information:

Command descriptions use these conventions:

Commands and keywords are in boldface text.

Arguments for which you supply values are in italic.

Square brackets ([ ]) mean optional elements.

Braces ({ }) group required choices, and vertical bars ( | ) separate the alternative elements.

Braces and vertical bars within square brackets ([{ | }]) mean a required choice within an optional element.

Interactive examples use these conventions:

Terminal sessions and system displays are in screen font.

Information you enter is in boldface screen font.

Nonprinting characters, such as passwords or tabs, are in angle 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 reader be careful. In this situation, you might do something that could result equipment damage or loss of data.

Timesaver Means the following will help you solve a problem. The tips information might not be troubleshooting or even an action, but could be useful information.

Related Publications

These documents provide complete information about the switch and are available from this URL:

You can order printed copies of documents with a DOC-xxxxxx= number from the sites and from the telephone numbers listed in the "Obtaining Documentation" section.

Note Switch requirements and procedures for initial configurations and software upgrades tend to change and therefore appear only in the release notes. Before installing, configuring, or upgrading the switch, refer to the release notes on for the latest information.

Release Notes for the Catalyst 2950 Switches, Cisco Release 12.1(11)EA1 (not orderable but is available on

Release Notes for the Catalyst 2950 LRE Switches, Cisco Release 12.1(11) YJ (not orderable but is available on

Note The Release Notes for the Catalyst 2950 Switches is for switches that are not LRE switches. For LRE switches, refer to the Release Notes for the Catalyst 2950 LRE Switches.

Catalyst 2950 Desktop Switch Software Configuration Guide (order number DOC-7811380=)

Catalyst 2950 Desktop Switch Command Reference (order number DOC-7811381=)

Catalyst 2950 Desktop Switch System Message Guide (order number DOC-7814233=)

Catalyst 2950 Desktop Switch Hardware Installation Guide (order number DOC-7811157=)

Catalyst GigaStack Gigabit Interface Converter Hardware Installation Guide (order number DOC-786460=)

Cluster Management Suite (CMS) online help (available only from the switch CMS software)

CWDM Passive Optical System Installation Note (not orderable but is available on

1000BASE-T Gigabit Interface Converter Installation Notes (not orderable but is available on

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