8-33
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 8 Configuring Switch-Based 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 security
feature that is subject to export restrictions. To use this feature, the cryptographic (encrypted) software
image must be installed on your switch. You must obtain authorization to use this feature and to
download the cryptographic software files from cisco.com. For more information, see the release notes
for this release.
This section contains this information:
Understanding SSH, page 8-33
Configuring SSH, page 8-34
Displaying the SSH Configuration and Status, page 8-37
For SSH configuration examples, see the “SSH Configuration Examples” section in the “Configuring
Secure Shell” chapter of the Cisco IOS Security Configuration Guide, Cisco IOS Release 12.2, at this
URL:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter0918
6a00800ca7d5.html
Note For complete syntax and usage information for the commands used in this section, see the command
reference for this release and the Cisco IOS Commands Master List, Release 12.2 at this URL:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_summary09186a008020b3
d8.html.

Understanding SSH

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 8-33
Limitations, page 8-34

SSH Servers, Integrated Clients, and Supported Versions

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 running the SSH server. 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.
SSH also supports these user authentication methods: