vidyaprakash

If you are having problems with telnet access, are you still able to access the router via its console? If so are there any error messages in the logs of the router?

Is it possible that the vty lines were configured with "no exec"? I believe that configuring no exec on the vty lines would produce symptoms like this. I have seen situations where someone configured no exec in the assumption that it was an abbreviation for no exec-timeout. Unfortunately no exec is a separate command and disables starting an exec session on the line. If the vty lines are configured with no exec, try configuring exec on the vty lines and let us know if this fixes the problem.

HTH

Rick