The authenticity of host 'server (xxx.yyy.zzz.www)' can't be established.
RSA key fingerprint is f7:ae:07:1a:78:11:17:c1:35:f7:1d:67:2a:cd:a9:2b.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'server' (RSA) to the list of known hosts.
user@server's password: 
Now try logging into the machine, with "ssh 'user@server'", and check in:
  .ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.