Some lil info (future refrence etc, tcp wrappers)
Probably TCP Wrappers and the old "double reverse lookup problem." Try adding an entry in /etc/hosts to refer back to your client(s) and make sure that your /etc/nsswitch.conf and /etc/hosts.conf are configured to honor "files" over DNS and NIS.
On Linux systems the /etc/inetd.conf is usually configured to run most programs under an access control and logging utility called "TCP Wrappers"
(/usr/sbin/tcpd). That utility refers to a couple of configuration files (/etc/hosts.allow, and /etc/hosts.deny) and it does some "paranoid" consistency checking to try and ensure that the client "is who he claims to be." The specifics of this paranoid checking are referred to as a "double reverse DNS lookup."
Linux uses a modular name services resolution system. Newer versions of Linux use the /etc/nsswitch.conf files to control the list of name services that are used for each name space (users/accounts, groups, hosts and networks, services, mail aliases, file server maps, etc). In most cases you wouldn't have to modify the nsswitch.conf to make it look at the /etc/hosts file. In other cases you might
other sites of refrence
Perl's NET::Telnet and NET::Telnet::CISCO modules may have what you're looking for. Check http://www.cpan.org.
(please watch what neg shit you say)