Par défaut, les switch L2/L3 ne font pas de routage, même si plusieurs interfaces Vlan sont configurées :
SW1#show ip interface brief | inc Vlan Vlan1 10.200.200.200 YES manual up up Vlan10 10.10.10.1 YES manual up up Vlan20 20.20.20.1 YES manual up up Vlan30 30.30.30.1 YES manual up up
SW1#show ip route Default gateway is not set Host Gateway Last Use Total Uses Interface ICMP redirect cache is empty
Une passerelle par défaut peut être configuré afin d’atteindre le switch à des fins administratifs
SW1#conf t
SW1(config)#ip default-gateway 10.200.200.1
SW1#show ip route
Default gateway is 10.200.200.1
Host Gateway Last Use Total Uses Interface
ICMP redirect cache is empty
Activation du routage niveau 3
SW1#conf t
SW1(config)#ip routing
SW1(config)#^Z
vérification de la table de routage
SW1#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
*Mar 1 02:41:51.271: %SYS-5-CONFIG_I: Configured from console by consoleset
20.0.0.0/24 is subnetted, 1 subnets
C 20.20.20.0 is directly connected, Vlan20
10.0.0.0/24 is subnetted, 2 subnets
C 10.200.200.0 is directly connected, Vlan1
C 10.10.10.0 is directly connected, Vlan10
30.0.0.0/24 is subnetted, 1 subnets
C 30.30.30.0 is directly connected, Vlan30
Dans ce cas « ip default gateway » n’est plus pris en compte,
« ip route » peut être utilisé pour spécifier une route statique
SW1#conf t
SW1(config)#ip route 0.0.0.0 0.0.0.0 10.200.200.1
SW1#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 10.200.200.1 to network 0.0.0.0
20.0.0.0/24 is subnetted, 1 subnets
C 20.20.20.0 is directly connected, Vlan20
10.0.0.0/24 is subnetted, 2 subnets
C 10.200.200.0 is directly connected, Vlan1
C 10.10.10.0 is directly connected, Vlan10
30.0.0.0/24 is subnetted, 1 subnets
C 30.30.30.0 is directly connected, Vlan30
S* 0.0.0.0/0 [1/0] via 10.200.200.1