Cisco 15327 - Manual (Page 316)

19-4
Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 19 Configuring Security for the ML-Series Card
Configuring SSH
To delete the RSA key pair, use the crypto key zeroize rsa global configuration command. After the
RSA key pair is deleted, the SSH server is automatically disabled.
Configuring the SSH Server
Beginning in privileged EXEC mode, follow these steps to configure the SSH server:
Command Purpose
Step 1 Router #configure terminal Enter global configuration mode.
Step 2 Router (config)# hostname hostname Configure a hostname for your ML-Series card.
Step 3 Router (config)# ip domain-name
domain_name
Configure a host domain for your ML-Series card.
Step 4 Router (config)# crypto key generate
rsa
Enable the SSH server for local and remote authentication on the
ML-Series card and generate an RSA key pair.
When you generate RSA keys, you are prompted to enter a modulus
length. The default modulus length is 512 bits. A longer modulus length
might be more secure, but it takes longer to generate and to use.
Step 5 Router (config)# ip ssh timeout
seconds
Specify the timeout 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 ML-Series card uses the
default timeout 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
timeout value returns to the default of 10 minutes.
Step 6 Router (config)# ip ssh
authentication-retries number
Specify the number of times that a client can reauthenticate to the
server. The default is 3; the range is 0 to 5.
Step 7 Router (config)# end Return to privileged EXEC mode.
Step 8 Router # show ip ssh
or
Router # show ssh
Displays the version and configuration information for your SSH
server.
Displays the status of the SSH server on the ML-Series card.
Step 9 Router # show crypto key mypubkey
rsa
Displays the generated RSA key pair associated with this ML-Series
card.
Step 10 Router # copy running-config
startup-config
(Optional) Save your entries in the configuration file.