This will be a real quick question, and responses should be sent directly to me, rather than the list please. I am trying to find more information about variable length subnetting. I have read the CIDR RFC, the VLS Table for IP v 4 RFC, and still am not sure about how to make it work. I have been accustomed to only subnetting class C networks. As I begin to implement the smurf amplifier blocking on our border router, it has come to be that I need to obviously get a better grasp. If any of you might suggest some recommended reading on this topic so I can quickly freshen up, it would be greatly appreciated. Thanks for answering the "junior" member of the list. Kevin Brown Huber & Associates, Inc. kbrown@primelink.com