I received way too many replies on this request. I really appreciate everybody who did reply, but please no more I found what I'm looking for in duplicates and triplicates.... For those others also interested here is what I was pointed to (sorted by number of pointers - almost 10 for aggis and 2-5 for others): 1. aggis - http://www.utdallas.edu/~pconnally/aggis 2. Net::CIDR::range2cidr(), Net::CIDR::Lite - http://search.cpan.org/dist/Net-IP/ 3. sipcalc - http://www.routemeister.net/ 4. http://perlmonks.thepen.com/79663.html Also several people have sent me their own perl scripts that that can be adapted to do what I wanted as well (if I needed it, which does not seem necessary given number of alternatives). Thanks you for those as well. Nanog community is really very helpfull. Please keep it up! ------- William Leibzon Elan Communications Inc. william@elan.net