CIDR
Shortage of class Bs => give out many class Cs instead of one class B address
- New problem: every class C network needs a routing entry !
- Solution: Classless Inter-domain Routing (CIDR). Also called “supernetting”
Key: allocate addresses such that they can be summarized.
- Share same higher order bits (I.e. prefix)
Routing tables and protocols must be capable of carrying a subnet mask.