Do you mean your Norton personal firewall? I don't use Norton but you'll find a link to Norton's firewall config instructions here
Firewall setup

Also check out UKBob's link here
http://www.gnutellaforums.com/showpo...10&postcount=9

Try the forum search, you also might find some info to help if you look back through old threads (search for configure norton internet security or something similar)