Supernet
From Wikipedia, the free encyclopedia
Supernetting is synonymous with Classless Inter-Domain Routing (CIDR) although CIDR is rather just the concept that is implemented when subnetting or supernetting.
In Internet networking terminology, a supernet is a block of contiguous subnetworks addressed as a single subnet.
Supernetting alleviates some of the issues with the original classful addressing scheme for IP addresses by allowing multiple networks address ranges to be combined, either to create a single larger network, or just for route aggregation to keep the "Internet Routing Table" (or any routing table) from growing too large.
For supernetting to work, you must be using static routing everywhere or be using a routing protocol which supports classless routing, such as RIPv2 or OSPF (or BGP for Exterior Routing) which can carry subnet mask information with the routing update. The older RIPv1 (or EGP for Exterior Routing) protocol only understands classful addressing, and therefore cannot transmit subnet mask information.
