Bgp 路由协议
拓扑图：
一：先配置所有路由器接口ip和回环IP，如图配置区域igp路由协议，（回环口只讲L0加入network）
二：配置bgp
1.ebgp建立邻居：
R1：
neighbor 192.168.30.1 remote-as 200
neighbor 192.168.30.1 update-source loopback 0
neighbor 192.168.30.1 ebgp-multihop 3
neighbor 192.168.50.1 remote-as 300
neighbor 192.168.50.1 update-source loopback 0
neighbor 192.168.50.1 ebgp-multihop 3
neighbor 192.168.70.1 remote-as 400
neighbor 192.168.70.1 update-source loopback 0
neighbor 192.168.70.1 ebgp-multihop 3
neighbor 192.168.90.1 remote-as 500
neighbor 192.168.90.1 update-source loopback 0
neighbor 192.168.90.1 ebgp-multihop 3
R2：
neighbor 192.168.10.1 remote-as 100
neighbor 192.168.10.1 update-source loopback 0
neighbor 192.168.10.1 ebgp-multihop 3
neighbor 192.168.50.1 remote-as 300
neighbor 192.168.50.1 update-source loopback 0
neighbor 192.168.50.1 ebgp-multihop 3
neighbor 192.168.70.1 remote-as 400
neighbor 192.168.70.1 update-source loopback 0
neighbor 192.168.70.1 ebgp-multihop 3
neighbor 192.168.90.1 remote-as 500
neighbor 192.168.90.1 update-source loopback 0
neighbor 192.168.90.1 ebgp-multihop 3
R3：
neighbor 192.168.10.1 remote-as 100
neighbor 192.168.10.1 update-source loopback 0
neighbor 192.168.10.1 ebgp-multihop 3
neighbor 192.168.30.1 remote-as 200
neighbor 192.168.30.1 update-source loopback 0
neighbor 192.168.30.1 ebgp-multihop 3
neighbor 192.168.70.1 remote-as 400
neighbor 192.168.70.1 update-source loopback 0
neighbor 192.168.70.1 ebgp-multihop 3
neighbor 192.168.90.1 remote-as 500
neighbor 192.168.90.1 update-source loopback 0
neighbor 192.168.90.1 ebgp-multihop 3
R4：
neighbor 192.168.10.1 remote-as 100
neighbor 192.168.10.1 update-source loopback 0
neighbor 192.168.10.1 ebgp-multihop 3
neighbor 192.168.30.1 remote-as 200
neighbor 192.168.30.1 update-source loopback 0
neighbor 192.168.30.1 ebgp-multihop 3
neighbor 192.168.50.1 remote-as 300
neighbor 192.168.50.1 update-source loopback 0
neighbor 192.168.50.1 ebgp-multihop 3
neighbor 192.168.90.1 remote-as 500
neighbor 192.168.90.1 update-source loopback 0
neighbor 192.168.90.1 ebgp-multihop 3
R5：
neighbor 192.168.10.1 remote-as 100
neighbor 192.168.10.1 update-source loopback 0
neighbor 192.168.10.1 ebgp-multihop 3
neighbor 192.168.30.1 remote-as 200
neighbor 192.168.30.1 update-source loopback 0
neighbor 192.168.30.1 ebgp-multihop 3
neighbor 192.168.50.1 remote-as 300
neighbor 192.168.50.1 update-source loopback 0
neighbor 192.168.50.1 ebgp-multihop 3
neighbor 192.168.70.1 remote-as 400
neighbor 192.168.70.1 update-source loopback 0
neighbor 192.168.70.1 ebgp-multihop 3
2.邻居配置完成后查看bgp邻居表：
R1#show ip bgp summary
192.168.30.1 4 200 7 7 1 0 0 00:03:54 0
192.168.50.1 4 300 5 6 1 0 0 00:02:55 0
192.168.70.1 4 400 4 5 1 0 0 00:01:59 0
192.168.90.1 4 500 5 5 1 0 0 00:01:11 0
R2#show ip bgp summary
192.168.10.1 4 100 16 16 1 0 0 00:12:22 0
192.168.50.1 4 300 6 8 1 0 0 00:00:00 0
192.168.70.1 4 400 13 14 1 0 0 00:10:17 0
192.168.90.1 4 500 12 13 1 0 0 00:09:57 0
R3#show ip bgp summary
192.168.10.1 4 100 15 14 1 0 0 00:11:32 0
192.168.30.1 4 200 4 4 1 0 0 00:00:09 0
192.168.70.1 4 400 13 13 1 0 0 00:10:20 0
192.168.90.1 4 500 13 13 1 0 0 00:09:57 0
R4#show ip bgp summary
192.168.10.1 4 100 5 4 1 0 0 00:01:41 0
192.168.30.1 4 200 5 4 1 0 0 00:01:31 0
192.168.50.1 4 300 4 4 1 0 0 00:01:24 0
192.168.90.1 4 500 4 4 1 0 0 00:01:25 0
R5#show ip bgp summary
192.168.10.1 4 100 5 5 1 0 0 00:01:04 0
192.168.30.1 4 200 5 4 1 0 0 00:01:21 0
192.168.50.1 4 300 5 5 1 0 0 00:01:12 0
192.168.70.1 4 400 4 4 1 0 0 00:01:35 0
EBGP邻居建立成功！
3.建立IBGP邻居：
R5：
R5(config)#router bgp 500
neighbor 56.1.1.6 remote-as 500
neighbor 67.1.1.7 remote-as 500
R6：
R6(config)#router bgp 500
neighbor 56.1.1.5 remote-as 500
neighbor 67.1.1.7 remote-as 500
R7：
R7(config)#router bgp 500
neighbor 67.1.1.6 remote-as 500
neighbor 56.1.1.5 remote-as 500
3.邻居配置完成后查看bgp邻居表：
R5#show ip bgp summary
56.1.1.6 4 500 15 16 1 0 0 00:12:26 0
67.1.1.7 4 500 4 4 1 0 0 00:00:32 0
192.168.10.1 4 100 32 32 1 0 0 00:28:22 0
192.168.30.1 4 200 32 31 1 0 0 00:28:40 0
192.168.50.1 4 300 32 32 1 0 0 00:28:31 0
192.168.70.1 4 400 31 31 1 0 0 00:28:54 0
R6#show ip bgp summary
56.1.1.5 4 500 14 13 1 0 0 00:10:26 0
67.1.1.7 4 500 13 13 1 0 0 00:10:12 0
R7#show ip bgp summary
56.1.1.5 4 500 4 4 1 0 0 00:00:23 0
67.1.1.6 4 500 15 15 1 0 0 00:12:04 0
IBGP邻居建立成功！
4.将所有路由器的回环口L1的网段和成都区域R5、R6、R7的网段network到bgp路由协议：
（这些网段之前并没有加入ospf协议的配置）
R1：
Network 192.168.20.0 mask 255.255.255.0
R2：
Network 192.168.40.0 mask 255.255.255.0
R3：
Network 192.168.60.0 mask 255.255.255.0
R4：
Network 192.168.80.0 mask 255.255.255.0
R5：
network 56.1.1.0 mask 255.255.255.0
R6：
network 67.1.1.0 mask 255.255.255.0
network 56.1.1.0 mask 255.255.255.0
R7:
network 67.1.1.0 mask 255.255.255.0
5.查看成都区域的bgp表
R6#show ip bgp
BGP table version is 1, local router ID is 67.1.1.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i56.1.1.0/24 56.1.1.5 0 100 0 i
* 0.0.0.0 0 32768 i
* i67.1.1.0/24 67.1.1.7 0 100 0 i
- i192.168.20.0 192.168.10.1 0 100 0 100 i
- i192.168.40.0 192.168.30.1 0 100 0 200 i
- i192.168.60.0 192.168.50.1 0 100 0 300 i
- i192.168.80.0 192.168.70.1 0 100 0 400 i
路由条目之前没有> 这样是不通的
6.所以需要配置下一跳通告命令：
R1：
router bgp 100
neighbor 192.168.30.1 next-hop-self
neighbor 192.168.90.1 next-hop-self
R2：
router bgp 200
neighbor 192.168.10.1 next-hop-self
neighbor 192.168.50.1 next-hop-self
R3：
router bgp 300
neighbor 192.168.30.1 next-hop-self
neighbor 192.168.70.1 next-hop-self
R4：
router bgp 400
neighbor 192.168.50.1 next-hop-self
neighbor 192.168.90.1 next-hop-self
R5：
router bgp 500
neighbor 192.168.10.1 next-hop-self
neighbor 192.168.70.1 next-hop-self
neighbor 56.1.1.6 next-hop-self
neighbor 67.1.1.7 next-hop-self
7.配置完成下一跳通告（路由更新重定向）命令后再次查看BGP表并ping bgp路由协议network的网段：
R6#show ip bgp
BGP table version is 7, local router ID is 67.1.1.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i56.1.1.0/24 56.1.1.5 0 100 0 i
*> 0.0.0.0 0 32768 i
* i67.1.1.0/24 67.1.1.7 0 100 0 i
*> 0.0.0.0 0 32768 i
*>i192.168.20.0 56.1.1.5 0 100 0 100 i
*>i192.168.40.0 56.1.1.5 0 100 0 200 i
*>i192.168.60.0 56.1.1.5 0 100 0 300 i
*>i192.168.80.0 56.1.1.5 0 100 0 400 i
出现了>
R6#ping 192.168.20.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.20.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 212/348/504 ms
R6#ping 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 428/472/512 ms
R6#ping 192.168.60.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.60.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 392/464/592 ms
R6#ping 192.168.80.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.80.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 204/321/392 ms
BGP 路由协议配置成功！（Ebgp最好物理接口建立邻居，Ibgp最好逻辑（回环）接口建立邻居）——我们这里没有严格要求此规则。