在一些網絡中，由於某種需要，配置多個動態學習路由協議，而在默認情況下各個路由協議之間不能互相學習路由信息（末梢路由器除外），那就需要我們通過手工配置實現路由器間互相學習路由信息。
在單協議網絡中，路由協議是把本地網段通告給本路由協議，在多協議的網絡中，在中間的路由器把本地網段通告給其他路由協議，即路由重分發
路由重分佈的作用:可以使得多種路由協議之間,多重廠商環境中進行路由信息交換
模擬實驗環境：IP分佈和拓撲如圖
根據拓撲圖，我們可以實現RIPV2、EIGRP、OSPF之間的兼容
配置命令：
router(config)#router 路由協議 參數
router(config-router)#network XXXX 通告本地網段
router(config-router)# redistribute 路由協議2 參數 metric 度量值
實驗步驟：
1、根據實驗圖配置基本步驟 略
2、配置路由器1 配置RIPV2路由協議
r1(config)#router rip //配置RIPV2
r1(config-router)#version 2
r1(config-router)#network 172.1.1.0
r1(config-router)#network 1.1.1.0
3、配置路由器3
r3(config)#router eigrp 10 //配置EIGRP AS=10
r3(config-router)#network 172.2.1.0
r3(config-router)#network 2.2.2.0
4、配置路由器4
r4(config)#router ospf 1 //配置OSPF AREA=0
r4(config-router)#network 172.3.1.0 0.0.0.255 area 0
r4(config-router)#network 3.3.3.0 0.0.0.255 area 0
5、配置路由器2
r2(config)#router rip
r2(config-router)#version 2
r2(config-router)#network 172.1.1.0
r2(config-router)#network 172.2.1.0
r2(config-router)#network 172.3.1.0
r2(config-router)#redistribute eigrp 10 metric 1
//EIGRP向RIPV2重定向，10爲AS號，跳數是1
r2(config-router)#redistribute ospf 1 metric 1
//OSPF向RIPV2重定向，OSPF 1爲進程號 metric 1爲跳數
r2(config)#router eigrp 10
r2(config-router)#network 172.1.1.0
r2(config-router)#network 172.2.1.0
r2(config-router)#network 172.3.1.0
r2(config-router)#redistribute rip metric 1544 20000 255 1 1500 //RIP向EIGRP重定向
r2(config-router)#redistribute ospf 1 metric 1544 20000 255 1 1500 //OSPF向EIGRP重定向
metric 後面值依次爲：帶寬、延遲、可靠性、負載、MTU
注意：順序不能改變
r2(config)#router ospf 1
r2(config-router)#network 172.1.1.0 0.0.0.255 area 0
r2(config-router)#network 172.2.1.0 0.0.0.255 area 0
r2(config-router)#network 172.3.1.0 0.0.0.255 area 0
r2(config-router)#redistribute rip metric 100 subnets
r2(config-router)#redistribute eigrp 10 metric 100 subnets
//metric 100 爲COST 值
六、測試聯通性
在路由器1上查看路由表
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
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
R 2.0.0.0/8 [120/1] via 172.1.1.1, 00:00:24, Serial0/0
R 3.0.0.0/8 [120/1] via 172.1.1.1, 00:00:24, Serial0/0
172.1.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.1.1.0/24 is directly connected, Serial0/0
R 172.1.0.0/16 [120/1] via 172.1.1.1, 00:00:24, Serial0/0
R 172.2.0.0/16 [120/1] via 172.1.1.1, 00:00:24, Serial0/0
R 172.3.0.0/16 [120/1] via 172.1.1.1, 00:00:24, Serial0/0
在路由器2上查看路由表
r2#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
R 1.0.0.0/8 [120/1] via 172.1.1.2, 00:00:06, Serial0/0
D 2.0.0.0/8 [90/2297856] via 172.2.1.2, 00:03:59, Serial0/1
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/65] via 172.3.1.2, 00:02:35, Serial0/2
172.1.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.1.1.0/24 is directly connected, Serial0/0
D 172.1.0.0/16 is a summary, 00:03:59, Null0
172.2.0.0/16 is variably subnetted, 2 subnets, 2 masks
D 172.2.0.0/16 is a summary, 00:03:59, Null0
C 172.2.1.0/24 is directly connected, Serial0/1
172.3.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.3.1.0/24 is directly connected, Serial0/2
D 172.3.0.0/16 is a summary, 00:03:55, Null0
在路由器3上查看路由表
r3#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
D EX 1.0.0.0/8 [170/7289856] via 172.2.1.1, 00:03:56, Serial0/0
2.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 2.2.2.0/24 is directly connected, Loopback0
D 2.0.0.0/8 is a summary, 00:04:40, Null0
3.0.0.0/32 is subnetted, 1 subnets
D EX 3.3.3.3 [170/7289856] via 172.2.1.1, 00:03:07, Serial0/0
D 172.1.0.0/16 [90/2681856] via 172.2.1.1, 00:04:31, Serial0/0
172.2.0.0/16 is variably subnetted, 2 subnets, 2 masks
D 172.2.0.0/16 is a summary, 00:04:40, Null0
C 172.2.1.0/24 is directly connected, Serial0/0
D 172.3.0.0/16 [90/2681856] via 172.2.1.1, 00:04:27, Serial0/0
在路由器4上查看路由表
r4#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
O E2 1.0.0.0/8 [110/100] via 172.3.1.1, 00:03:35, Serial0/0
O E2 2.0.0.0/8 [110/100] via 172.3.1.1, 00:03:35, Serial0/0
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
172.1.0.0/16 is variably subnetted, 2 subnets, 2 masks
O 172.1.1.0/24 [110/128] via 172.3.1.1, 00:03:35, Serial0/0
O E2 172.1.0.0/16 [110/100] via 172.3.1.1, 00:03:35, Serial0/0
172.2.0.0/16 is variably subnetted, 2 subnets, 2 masks
O E2 172.2.0.0/16 [110/100] via 172.3.1.1, 00:03:35, Serial0/0
O 172.2.1.0/24 [110/128] via 172.3.1.1, 00:03:35, Serial0/0
172.3.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.3.1.0/24 is directly connected, Serial0/0
O E2 172.3.0.0/16 [110/100] via 172.3.1.1, 00:03:35, Serial0/0
利用PING命令測試
r1#ping 2.2.2.2 source 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
Packet sent with a source address of 1.1.1.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 68/123/208 ms
r1#ping 3.3.3.3 source 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
Packet sent with a source address of 1.1.1.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 52/105/200 ms