Cisco :: Configuring SSH

PRECONDITION: You need a K9 IOS (newer than 12.1) to enable SSH

1) You MUST set a host name
hostname ciscolab

2) You MUST set a ip domain name
ip domain-name mydomain.com

3) You MUST enable aaa new-model OR set “login local” under vty configuration but not just “login”
aaa new-model

4) You MUST create a user
username sshtest password 0 sshpass

5) You MUST generate RSA keys
crypto key generate rsa

if you have RSA keys before you will receive a message, type yes
% You already have RSA keys defined named ciscolab.mydomain.com.
% Do you really want to replace them? [yes/no]: yes

it will ask for modulus size, 1024 is fine (it depends your security needs)
How many bits in the modulus [512]: 1024

6) You MUST set vty access method to all OR ssh (if you chose ssh telnet will be disabled)
line vty 0 4
transport input ssh

Reference ::
http://cisco-network.com/hands-on/ssh-cisco/
http://www.cisco.com/en/US/tech/tk583/tk617/technologies_tech_note09186a00800949e2.shtml#diagram