Cisco Systems 2950 Configuring the Switch for Secure Shell

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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide

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Chapter9 Configuring Switch-Ba sed Authentication Configuring the Switch for Secure Shell

Configuring the Switch for Secure Shell

This section describes how to configure the Secure Shell (SSH) feature. SSH is a cryptographic se curity

feature that is subject to export restrictions. To use this feature, the cryptographic (encrypted) enhanced

software image (EI) must be installed on your switch. You must obtain authorization to use this f eat ure

and to download the cryptographic software files from Cisco.com. For more information, refer to the

release notes for this release.

This section contains this information:

•Understanding SSH, page 9-33

•Configuring SSH, page 9-34

•Displaying the SSH Configuration and Status, page 9-37

For SSH configuration examples, refer to the “SSH Configuration Examples” section in the

“Configuring Secure Shell” chapter of the Cisco IOS Security Configuration Guide, Cisco IOS

Release12.2, at this URL:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fsecur_c/fothersf/

scfssh.htm

Note For complete syntax and usage information for the commands used in this section, refer to the command

reference for this release and the command reference for Cisco IOS Release 12.2 at this URL:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/index.htm.

SSH is a protocol that provides a secure, remote connection to a device. SSH provides more security for

remote connections than Telnet does by providing strong encryption when a device is authenticated. This

software release supports SSH version 1 (SSHv1) and SSH version 2 (SSHv2).

This section consists of these topics:

•SSH Servers, Integrated Clients, and Supported Versions, page 9-33

•Limitations, page 9-34

The SSH feature has an SSH server and an SSH integrated client, which are applications that run on the

switch. You can use an SSH client to connect to a switch runn ing the SSH s erv er. The SSH server works

with the SSH client supported in this release and with non-Cisco SSH clients. The SSH client also works

with the SSH server supported in this release and with non-Cisco SSH servers.

The switch supports an SSHv1 or an SSHv2 server.

The switch supports an SSHv1 client.

SSH supports the Data Encryption Standard (DES) encryption algorithm, the Triple DES (3DES)

encryption algorithm, and password-based user authentication.