Disable SSH host checking.

when access ssh to any host, it will ask us to accept the certificate,

$ ssh root@10.8.72.253
The authenticity of host '10.8.72.253 (10.8.72.253)' can't be established.
DSA key fingerprint is 35:93:23:a6:84:6f:26:c2:53:47:84:f7:a3:00:40:8e.
Are you sure you want to continue connecting (yes/no)?


To avoid the message, create 'config' file in ~/.ssh and add content as below

$ cat ~/.ssh/config
Host 10.*.*.*
   StrictHostKeyChecking no
   UserKnownHostsFile=/dev/null

then, next time you ssh it ask only the password

$ ssh admin@10.8.72.253
Warning: Permanently added '10.8.72.253' (DSA) to the list of known hosts.
admin@10.8.72.253's password: