IP Routing
Classless routing
- route entries include
- destination
- next-hop
- mask (prefix-length) indicating size of address space described by the entry
Longest match
- for a given destination, find longest prefix match in the routing table
- example: destination is 35.35.66.42
- routing table entries are 35.0.0.0/8, 35.35.64.0/19 and 0.0.0.0/0
- All these routes match, but the /19 is the longest match