Classless addressing
 
 
- Forget old Class A, Class B, Class C terminology and restrictions
- Internet routing and address management today is classless
- CIDR = Classless Inter-Domain Routing
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- routing does not assume that class A,B,C implies prefix length /8,/16,/24
 
- VLSM = Variable-Length Subnet Masks
- 
- routing does not assume that all subnets are the same size