EIGRP和OSPF做双点双向重分发 第一种情况： 1，R1,R2,R3,R4初始配置 R1 conf t int l 0 ip add 1.1.1.1 255.255.255.255 int f0/0 ip add 1.1.123.1 255.255.255.0 no shut router eigrp 1 no auto net 1.1.1.1 0.0.0.0 net 1.1.123.0 0.0.0.255 end R2 conf t int l 0 ip add 1.1.2.2 255.255.255.255 int f0/0 ip add 1.1.123.2 255.255.255.0 no shut int s1/0 ip add 1.1.234.2 255.255.255.0 encap f no arp f no frame inv frame map ip 1.1.234.4 204 b frame map ip 1.1.234.3 204 b no shut ip ospf p 0 router ospf 1 router-id 1.1.2.2 net 1.1.234.2 0.0.0.0 a 0 net 1.1.2.2 0.0.0.0 a 0 router eigrp 1 no auto net 1.1.2.2 0.0.0.0 net 1.1.123.0 0.0.0.255 end R3 conf t int l 0 ip add 1.1.3.3 255.255.255.255 int f 0/0 ip add 1.1.123.3 255.255.255.0 no shut int s1/0 ip add 1.1.234.3 255.255.255.0 encap f no arp f no frame inv frame map ip 1.1.234.4 304 b frame map ip 1.1.234.2 304 b no shut ip ospf p 0 router ospf 1 router-id 1.1.3.3 net 1.1.234.3 0.0.0.0 a 0 net 1.1.3.3 0.0.0.0 a 0 router eigrp 1 no auto net 1.1.3.3 0.0.0.0 net 1.1.123.0 0.0.0.255 end R4 conf t int l 0 ip add 1.1.4.4 255.255.255.255 int s1/0 ip add 1.1.234.4 255.255.255.0 encap f no arp f no frame inv frame map ip 1.1.234.2 402 b frame map ip 1.1.234.3 403 b no shut router ospf 1 router-id 1.1.4.4 nei 1.1.234.2 nei 1.1.234.3 net 1.1.234.4 0.0.0.0 a 0 net 1.1.4.4 0.0.0.0 a 0 end 到这里，所有的EIGRP和OSPF邻居关系都建立好了。 2，在R2和R3上做双点双向重分发 R2 router eigrp 1 redistribute ospf 1 metric 10000 100 255 1 1500 router ospf 1 redistribute eigrp 1 metric 100 metric-type 1 subnets end R3 router eigrp 1 redistribute ospf 1 metric 10000 100 255 1 1500 router ospf 1 redistribute eigrp 1 metric 100 metric-type 1 subnets end 重分发完成， 验证 R1路由表 R1#sh ip route Gateway of last resort is not set 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks D EX 1.1.4.4/32 [170/284160] via 1.1.123.3, 00:01:03, FastEthernet0/0 [170/284160] via 1.1.123.2, 00:01:03, FastEthernet0/0 D 1.1.3.3/32 [90/156160] via 1.1.123.3, 00:08:44, FastEthernet0/0 D 1.1.2.2/32 [90/156160] via 1.1.123.2, 00:08:44, FastEthernet0/0 C 1.1.1.1/32 is directly connected, Loopback0 C 1.1.123.0/24 is directly connected, FastEthernet0/0 D EX 1.1.234.0/24 [170/284160] via 1.1.123.3, 00:02:51, FastEthernet0/0 [170/284160] via 1.1.123.2, 00:02:51, FastEthernet0/0 R4路由表 R4#sh ip route Gateway of last resort is not set 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks C 1.1.4.4/32 is directly connected, Loopback0 O 1.1.3.3/32 [110/65] via 1.1.234.3, 00:00:14, Serial1/0 O 1.1.2.2/32 [110/65] via 1.1.234.2, 00:00:14, Serial1/0 O E1 1.1.1.1/32 [110/164] via 1.1.234.3, 00:00:14, Serial1/0 [110/164] via 1.1.234.2, 00:00:14, Serial1/0 O E1 1.1.123.0/24 [110/164] via 1.1.234.3, 00:00:14, Serial1/0 [110/164] via 1.1.234.2, 00:00:14, Serial1/0 C 1.1.234.0/24 is directly connected, Serial1/0 第二种情况 在R1的S1/2接口接入R5，并启用RIPV2 R5 conf t int s1/2 ip add 192.168.45.5 255.255.255.0 no shut router rip ver 2 no auto net 192.168.45.0 end R1 conf t int s1/2 no shut ip add 192.168.45.4 255.255.255.0 router rip ver 2 no au net 192.168.45.0 end 把RIP再分发到EIGRP1中 router eigrp 1 redistribute rip metric 10000 100 255 1 1500 end 这时看R2和R3上的路由表 R2(config)#do 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 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks O 1.1.4.4/32 [110/65] via 1.1.234.4, 00:31:58, Serial1/0 D 1.1.3.3/32 [90/156160] via 1.1.123.3, 00:05:56, FastEthernet0/0 C 1.1.2.2/32 is directly connected, Loopback0 D 1.1.1.1/32 [90/156160] via 1.1.123.1, 00:05:56, FastEthernet0/0 C 1.1.123.0/24 is directly connected, FastEthernet0/0 C 1.1.234.0/24 is directly connected, Serial1/0 O E1 192.168.45.0/24 [110/164] via 1.1.234.3, 00:05:59, Serial1/0 R2(config)#do ping 192.168.45.5 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.45.5, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) 仔细查看路由表可以发现，R2到192.168.45.0网段下一跳是1.1.234.2，也就是R3的S1/0接口，但是拓扑上表明下一跳为R1的F0 /0接口为最佳路径。为什么会出现这样的情况呢？ 我们知道，EIGRP的AD(管理距离）有两种情况： 1，当收到内部路由时，AD为90，路由表里的标识为“D” 2，当收到外部转发的路由是，AD为170，路由表里的标识为“ D EX” 当R1把RIP再分发到EIGRP1中的时候，R2和R3的收到192.168.45.0网段为“D EX"标识（可以通过shou ip bgptop命令校验)，这时EIGRP的AD为170，当R2把EIGRP1再分发到OSPF中后，因为的OSPF的AD为110，R3会从R1和R2 这个两个路由器上收到192.168.45.0这个路由条目，根据路由选路原则，R3会优先选择OSPF协议收到的路由，所以在路由表上显示“OE1”， 这样的结果会造成数据包在R4和R2之间震荡， 用trace命令验证 R2(config)#do trace 192.168.45.5 Type escape sequence to abort. Tracing the route to 192.168.45.5 1 1.1.234.4 252 msec 232 msec 232 msec 2 1.1.234.3 432 msec 308 msec 304 msec 3 * * * 4 1.1.234.4 576 msec 612 msec 480 msec 5 1.1.234.3 720 msec 464 msec 648 msec 6 * * * 7 1.1.234.4 528 msec 684 msec 552 msec 8 1.1.234.3 888 msec 932 msec 672 msec 9 * * * …… R3上也会出现相同的情况 解决方法 将R2和R3上OSPF的AD修改为大于170 R2 conf t access 10 permit 192.168.45.0 0.0.0.255 router ospf 1 distance 180 1.1.3.3 0.0.0.0 10 end R3 conf t access 10 permit 192.168.45.0 0.0.0.255 router ospf 1 distance 180 1.1.2.2 0.0.0.0 10 end 验证R2，R3，R4路由表 R2(config)#do 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 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks O 1.1.4.4/32 [110/65] via 1.1.234.4, 00:11:38, Serial1/0 D 1.1.3.3/32 [90/156160] via 1.1.123.3, 00:11:38, FastEthernet0/0 C 1.1.2.2/32 is directly connected, Loopback0 D 1.1.1.1/32 [90/156160] via 1.1.123.1, 00:11:38, FastEthernet0/0 C 1.1.123.0/24 is directly connected, FastEthernet0/0 C 1.1.234.0/24 is directly connected, Serial1/0 D EX 192.168.45.0/24 [170/284160] via 1.1.123.1, 00:11:38, FastEthernet0/0 R3(config)#do 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 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks O 1.1.4.4/32 [110/65] via 1.1.234.4, 00:01:27, Serial1/0 C 1.1.3.3/32 is directly connected, Loopback0 D 1.1.2.2/32 [90/156160] via 1.1.123.2, 00:01:27, FastEthernet0/0 D 1.1.1.1/32 [90/156160] via 1.1.123.1, 00:01:27, FastEthernet0/0 C 1.1.123.0/24 is directly connected, FastEthernet0/0 C 1.1.234.0/24 is directly connected, Serial1/0 D EX 192.168.45.0/24 [170/284160] via 1.1.123.1, 00:01:27, FastEthernet0/0 R4#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 1.0.0.0/8 is variably subnetted, 6 subnets, 2 masks C 1.1.4.4/32 is directly connected, Loopback0 O 1.1.3.3/32 [110/65] via 1.1.234.3, 00:19:57, Serial1/0 O 1.1.2.2/32 [110/65] via 1.1.234.2, 00:19:57, Serial1/0 O E1 1.1.1.1/32 [110/164] via 1.1.234.3, 00:19:57, Serial1/0 [110/164] via 1.1.234.2, 00:19:57, Serial1/0 O E1 1.1.123.0/24 [110/164] via 1.1.234.3, 00:19:57, Serial1/0 [110/164] via 1.1.234.2, 00:19:57, Serial1/0 C 1.1.234.0/24 is directly connected, Serial1/0 O E1 192.168.45.0/24 [110/164] via 1.1.234.3, 00:12:25, Serial1/0 [110/164] via 1.1.234.2, 00:12:25, Serial1/0
