Chapter 1
Configuring Switch-Based Authentication
Configuring the SSH Server
Beginning in privileged EXEC mode, follow these steps to configure the SSH server:
Command
Step 1
configure terminal
Step 2
ip ssh version [1 | 2]
Step 3
ip ssh {timeout seconds |
authentication-retries number}
Step 4
line vty line_number
[ending_line_number]
transport input ssh
Step 5
end
Step 6
show ip ssh
or
show ssh
Step 7
copy running-config startup-config
To return to the default SSH control parameters, use the no ip ssh {timeout | authentication-retries}
global configuration command.
OL-25303-03
Purpose
Enter global configuration mode.
(Optional) Configure the switch to run SSH Version 1 or SSH Version 2.
1—Configure the switch to run SSH Version 1.
•
2—Configure the switch to run SSH Version 2.
•
If you do not enter this command or do not specify a keyword, the SSH
server selects the latest SSH version supported by the SSH client. For
example, if the SSH client supports SSHv1 and SSHv2, the SSH server
selects SSHv2.
Configure the SSH control parameters:
Specify the time-out value in seconds; the default is 120 seconds. The
•
range is 0 to 120 seconds. This parameter applies to the SSH
negotiation phase. After the connection is established, the switch uses
the default time-out values of the CLI-based sessions.
By default, up to five simultaneous, encrypted SSH connections for
multiple CLI-based sessions over the network are available (session 0
to session 4). After the execution shell starts, the CLI-based session
time-out value returns to the default of 10 minutes.
Specify the number of times that a client can re-authenticate to the
•
server. The default is 3; the range is 0 to 5.
Repeat this step when configuring both parameters.
(Optional) Configure the virtual terminal line settings.
Enter line configuration mode to configure the virtual terminal line
•
settings. For line_number and ending_line_number, specify a pair of
lines. The range is 0 to 15.
Specify that the switch prevent non-SSH Telnet connections. This
•
limits the router to only SSH connections.
Return to privileged EXEC mode.
Show the version and configuration information for your SSH server.
Show the status of the SSH server connections on the switch.
(Optional) Save your entries in the configuration file.
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
Configuring the Switch for Secure Shell
1-47