It isn't a "ban". You need to request an exemption in this sub-forum
http://www.project1999.org/forums/forumdisplay.php?f=25
and follow these instructions:
IP Exemption: This is for requesting to be exempt from the limit of 1 connection per IP Address. You may request exemption if you have more than 1 real person playing from the same IP. When posting for this, please include the account names of every person that will be playing from the same IP.