重分布―双点双向
要求：先在R2上将RIP重分布到OSPF，再将R4上的RIP发布到OSPF，观察在R2和R4上学到的路由信息。
实验结果：在R4上学到R3的路由为O E2型的，在R2上学到的R3的路由为R型的。
原因：R2将R3的路由先重分布到OSPF中，在R4上从OSPF上学到的R3路由管理距离为110，而从rip上学到的管理距离为120，所以R4接收从OSPF上学到的路由，类型为O E2,由于R4是通过LSA 5学到的路由，即通过DV算法学到的，水平分割，所以R4不会再将从RIP上学到的路由路由从R4上面的接口重分发出去，所以R2上没有O E2型的。
图例：
R1
en
conf t
hos r1
int e0/0
ip add 192.168.12.1 255.255.255.0
no shu
exi
int e0/1
ip add 192.168.14.1 255.255.255.0
no shu
exi
int lo 0
ip add 1.1.1.1 255.255.255.0
exi
router ospf 1
net 192.168.12.0 0.0.0.255 ar 0
net 192.168.14.0 0.0.0.255 ar 0
net 1.1.1.0 0.0.0.255 ar 0
exi
R2
en
conf t
hos r2
int e0/0
ip add 192.168.12.2 255.255.255.0
no shu
exi
int e0/1
ip add 192.168.23.2 255.255.255.0
no shu
exi
router ospf 1
net 192.168.12.0 0.0.0.255 ar 0
redistribute rip subnets
exi
router rip
ver 2
no au
net 192.168.23.0
exi
R3
en
conf t
hos r3
int e0/1
ip add 192.168.23.3 255.255.255.0
no shu
exi
int e0/0
ip add 192.168.34.3 255.255.255.0
no shu
exi
int lo 0
ip add 3.3.3.3 255.255.255.0
exi
int e0/2
ip add 192.168.1.9 255.255.255.0
no shu
exi
router rip
ver 2
no au
net 192.168.23.0
net 192.168.34.0
net 3.3.3.0
net 192.168.1.0
exi
R4
en
conf t
hos r4
int e0/0
ip add 192.168.34.4 255.255.255.0
no shu
exi
int e0/1
ip add 192.168.14.4 255.255.255.0
no shu
exi
router ospf 1
net 192.168.14.0 0.0.0.255 ar 0
redistribute rip subnets
exi
router rip
ver 2
no au
net 192.168.34.0
exi
r1#sh 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, Ethernet0/0
1.0.0.0/24 is subnetted, 1 subnets
C
1.1.1.0 is directly connected, Loopback0
C
192.168.14.0/24 is directly connected, Ethernet0/1
3.0.0.0/24 is subnetted, 1 subnets
O E2
3.3.3.0 [110/20] via 192.168.12.2, 00:01:54, Ethernet0/0
O E2 192.168.23.0/24 [110/20] via 192.168.12.2, 00:02:08, Ethernet0/0
O E2 192.168.34.0/24 [110/20] via 192.168.12.2, 00:01:54, Ethernet0/0
O E2 192.168.1.0/24 [110/20] via 192.168.12.2, 00:01:54, Ethernet0/0
r2#sho 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, Ethernet0/0
1.0.0.0/32 is subnetted, 1 subnets
O
1.1.1.1 [110/11] via 192.168.12.1, 00:02:28, Ethernet0/0
O
192.168.14.0/24 [110/20] via 192.168.12.1, 00:02:28, Ethernet0/0
3.0.0.0/24 is subnetted, 1 subnets
R
3.3.3.0 [120/1] via 192.168.23.3, 00:00:22, Ethernet0/1
C
192.168.23.0/24 is directly connected, Ethernet0/1
R
192.168.34.0/24 [120/1] via 192.168.23.3, 00:00:22, Ethernet0/1
R
192.168.1.0/24 [120/1] via 192.168.23.3, 00:00:22, Ethernet0/1
r4#sho ip rou
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
O
192.168.12.0/24 [110/20] via 192.168.14.1, 00:00:05, Ethernet0/1
1.0.0.0/32 is subnetted, 1 subnets
O
1.1.1.1 [110/11] via 192.168.14.1, 00:00:05, Ethernet0/1
C
192.168.14.0/24 is directly connected, Ethernet0/1
3.0.0.0/24 is subnetted, 1 subnets
O E2
3.3.3.0 [110/20] via 192.168.14.1, 00:00:05, Ethernet0/1
O E2 192.168.23.0/24 [110/20] via 192.168.14.1, 00:00:05, Ethernet0/1
C
192.168.34.0/24 is directly connected, Ethernet0/0
O E2 192.168.1.0/24 [110/20] via 192.168.14.1, 00:00:05, Ethernet0/1