Hi Ramesh,
You are able to ping the Host but unable to Login via Putty??
Have you built that host newly??? if so please check the status of "Permit Root Login" where it has to be given as YES (bydefault it is NO).
To do this please follow the steps below:
1.Login to the Physical Host directly with root login (ESX Host through Service Console by pressing ALT+F1)
2. Type as follow:
-> vi/etc/ssh/sshd_config (press ENTER)
-> In the file content go the 2nd page you will find 'Permit Root Login No'
-> Press INSERT or I key, change/edit permit root login from NO to YES
-> Press Esc key & type ':qw' to save & quit from editor
-> Restart SSH Service : by typing - 'service sshd restart'
-> Resart Network Services : by typing - 'service network restart' (this command is optional but resolves the issue if their is any Network problem)
Hope it should allow you to login to that Host via Putty.Please let know if the problem persist again..Thanks
