MP-BGP有路由，但是PING不通

尊敬的用户您好：

首先路由表中有路由不一定能PING通，你查看这条路由的NEXT-HOP是否可达。

一般都是下一跳是黑洞路由所以导致PING不通。但是建议你试试一下几个命令，做一个全面的查找。

1，show ip bgp ex x.x.x.x 查看下这条路由的信息

2，show ip bgp 看是否有最佳路径 >

3，ping X.X.X.X sou x.x.x.x 带源ping

中国电信提供最优质的网络通讯服务，如需相关业务，可以直接通过电信网上营业厅或者实体营业厅查询。

实验步骤： 1. R1上的配置：Router>Router>enRouter#conf tRouter(config)#host r1r1(config)#int e0r1(config-if)#ip add 172.16.1.1 255.255.255.0r1(config-if)#no shutdown r1(config-if)#exitr1(config)#int s0r1(config-if)#ip add 172.16.2.1 255.255.255.0r1(config-if)#no shutdown r1(config-if)#clock rate 56000r1(config-if)#no shutdown r1(config-if)#exitr1(config)#router ripr1(config-router)#net 172.16.0.0r1(config-router)#^Z RIP协议启用前的路由表r1#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route Gateway of last resort is not setC 172.16.1.0/24 is directly connected, Ethernet0C 172.16.2.0/24 is directly connected, Serial0RIP协议启用后的路由表r1#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route Gateway of last resort is not setC 172.16.1.0/24 is directly connected, Ethernet0C 172.16.2.0/24 is directly connected, Serial0R 172.16.3.0/24 [120/1] via 172.16.2.2, 00:01:37, Serial0R 172.16.4.0/24 [120/1] via 172.16.2.2, 00:07:21, Serial0R 172.16.5.0/24 [120/2] via 172.16.2.2, 00:05:21, Serial0 2. R2上的配置：Router>Router>enRouter#conf tRouter(config)#host r2r2(config)#int s1r2(config-if)#ip add 172.16.2.2 255.255.255.0r2(config-if)#no shutdown r2(config-if)#exitr2(config)#int s0r2(config-if)#ip add 172.16.4.0 255.255.255.0r2(config-if)#ip add 172.16.4.1 255.255.255.0r2(config-if)#clock rate 56000r2(config-if)#no shutdown r2(config-if)#exitr2(config)#int e0r2(config-if)#ip add 172.16.3.1 255.255.255.0r2(config-if)#no shutdown r2(config-if)#exitr2(config)#router ripr2(config-router)#net 172.16.0.0r2(config-router)#^Z r2#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route Gateway of last resort is not setC 172.16.2.0/24 is directly connected, Serial1C 172.16.3.0/24 is directly connected, Ethernet0C 172.16.4.0/24 is directly connected, Serial0R 172.16.1.0/24 [120/1] via 172.16.2.1, 00:09:13, Serial1R 172.16.5.0/24 [120/1] via 172.16.4.2, 00:09:13, Serial0 3. R3上的配置：Router>Router>enRouter#conf tRouter(config)#int s1Router(config-if)#ip add 172.16.4.2 255.255.255.0Router(config-if)#no shutdown Router(config-if)#exitRouter(config)#int e0Router(config-if)#ip add 172.16.5.1 255.255.255.0Router(config-if)#no shutdown Router(config-if)#exitRouter(config)#host r3r3(config)#r3(config)#router ripr3(config-router)#net 172.16.0.0r3(config-router)#^Z r3#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route Gateway of last resort is not setC 172.16.4.0/24 is directly connected, Serial1C 172.16.5.0/24 is directly connected, Ethernet0R 172.16.1.0/24 [120/1] via 172.16.4.1, 00:05:32, Serial1R 172.16.2.0/24 [120/1] via 172.16.4.1, 00:08:19, Serial1R 172.16.3.0/24 [120/1] via 172.16.4.1, 00:05:32, Serial1 4. 测试：r1#r1#pingProtocol [ip]:Target IP address: 172.16.5.2Repeat count [5]: Datagram size [100]: Timeout in seconds [2]:Extended commands [n]: Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 172.16.5.2, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms PC 上的配置为：PC1：IP为172.16.1.2 网关：172.16.1.1PC2：IP为172.16.3.2 网关：172.16.3.1PC3：IP为172.16.5.2 网关：172.16.5.1

---