A.Redirect B.Sourcequench C.Echoreply D.estinationunreachable
A.route ip172.0.0.0255.0.0.0s0 B.ip route0.0.0.00.0.0.0172.16.20.1 C.ip route0.0.0.0255.255.255.255172.16.20.1 D.route ip0.0.0.0255.255.255.0172.16.10.1150
A.255.255.255.252 B.255.255.255.128 C.255.255.0.0 D.255.255.255.192