i added the option and tried a sample code but it's not helping... I'm just trying ls command on remote m/c with sample script. Pls see the below output it's asking for host key verification even after adding the ssh_option you specified... <snip> Running remote cmds Wed Mar 23 11:09:21 IST 2011 output of ls The authenticity of host 'test1 (192.168.1.1)' can't be established. RSA key fingerprint is 48:0b:26:bf:5d:54:c9:c3:cc:7a:25:20:5e:14:b6:d0. Are you sure you want to continue connecting (yes/no)? <snip>