LAN IP configuration

Hi,

I have Winproxy setup on LAN server, and I have lost the password for that. As that server is old and tacky, I don’t want to mess with it. Trying to access it remotely, gives an error saying that my IP is blacklisted. It only gives internet access to certain IP addresses. Is there a way to get a list of those IP’s other than by manual changing and checking each and every IP one by one?

Thanks,
Girish.