Everyone... I appreciate everyone's response to my basic questions on these topics. I've got a truckload of sources to read from now. :=) For the record, and the archives... the most useful documents I was referred to, or found most helpful were: RFC1518- An Architecture for IP Address Allocation with CIDR http://www.arin.net/rfc/rfc1518.txt RFC1466-Guidelines for Management of IP Address Space http://www.arin.net/rfc/rfc1466.txt RFC1519-CIDR: an Address Assignment and Aggregation Study http://www.arin.net/rfc/rfc1519.txt RFC1878-Variable Length Subnet Table for IPv4 http://www.arin.net/rfc/rfc1878.txt CIDR FAQ http://www.rain.net/faqs/cidr.faq.html Understanding IP Addressing: Everything you Ever Wanted to Know http://www.3com.com/nsc/501302.html Once again, thanks to everyone who assisted me in locating this information, and hopefully with this mail in the archives, the next "junior" won't have to ask the question.