Kiểm tra bảng route tại SaiGon:SaiGon#show ip routeGateway of last resort is not set172.16.0.0/16 is variably subnetted, 2 subnets, 2 masksC 172.16.0.0/30 is directly connected, Serial0/
1B 172.16.1.0/24 [20/0] via 172.16.0.1, 00:00:3610.0.0.0/30 is subnetted,
1 subnetsC 10.0.0.0 is dir[r]