I'll have an application running in Linux Server, and I'll have to establish a secure connection between both for to encrypt the information trough the tunnel.

1. Depends on IOS version of your cisco router. Make sure your IOS supports ssh and then you have to generate rsa keys, give hostname, domain name to router and under line vty yuo have to put login ssh. This makes you ready for ssh from server.
   To start a ssh session to server from router type
   ssh -l <username> -c <des or 3des> <server IP>
2. Here is an SSH FAQ from Cisco:

   http://www.cisco.com/en/us/tech/tk583/tk…

Tags: red hat linux, mandrake linux