sorry if I didn't explained it:
you can use . for saying "telnet yourself", for example if I'm in serverA as normal user, and I want to login as root I can say:

[serverA] /home/user> telnet . (instead of using the name serverA)
username: root
password: xxxxx

then the prompt would looks like:
[serverA] /home/user# (now I'm root in the same machine)

The problem is, that for a strange reason, the server does not recognize the "." as itself.. even though if I try with the servername (serverA) or the Ip address the login is succesfull.

I hope this is clear and someone can help me.