Hi Akanksha,
Sorry, that doesn't bring raise any immediate solution issues to mind. I'd recommend consulting with your unix admins for that issue and make sure that the connection outside of RA is working successfully, then get details on the problem/solution - as it may impact the field values inside of RA.
I just did a google search and while this solution may not apply to you it does look like they're enabling debug to get additional information which might help you understand why you're having the problem you're having.
ssh - Linux closing connection after successful login - Server Fault
Kind regards,
Gregg