Default Route

Router에 정확하게 입력되어 있는 주소가 아닌 경우에 나갈 Gateway 지정하는 것.

ip  route  0.0.0.0  0.0.0.0  172.16.2.2

0.0.0.0 : 모든 ip.

어떤 경우에 사용?

Stub Network. ( 나가는 길이 하나뿐인 네트워크 )

R1#show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C    192.168.12.0/24 is directly connected, Serial1/0

S    192.168.23.0/24 [1/0] via 192.168.12.2

C    192.168.1.0/24 is directly connected, Loopback0

S    192.168.2.0/24 [1/0] via 192.168.12.2

S    192.168.3.0/24 [1/0] via 192.168.12.2

이런 경우 2, 4, 5번째 게이트웨이가 같으므로 default route 를 설정하는게 좋다.

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default route 설정하는 화면.

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R1(config)#ip route 0.0.0.0 0.0.0.0 192.168.12.2

R1(config)#end

R1#show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is 192.168.12.2 to network 0.0.0.0

C    192.168.12.0/24 is directly connected, Serial1/0

C    192.168.1.0/24 is directly connected, Loopback0

S*   0.0.0.0/0 [1/0] via 192.168.12.2