实验拓扑
基本配置：
R1
L0:1.1.1.1/32
L1:11.1.1.1/32
E1/0:10.1.12.1/24
E1/1:10.1.14.1/24
R2
L0:2.2.2.2/32
L1:22.2.2.2/32
E1/0:10.1.12.2/24
E1/1:10.1.24.2/24
R4
L0:4.4.4.4/32
L1:44.4.4.4/32
E1/0:10.1.24.4/24
E1/1:10.1.14.4/24
配置IGP（RIP）：
R1
router rip
version 2
network 1.0.0.0
network 10.0.0.0
no auto-summary
R2
router rip
version 2
network 2.0.0.0
network 10.0.0.0
no auto-summary
R4
router rip
version 2
network 4.0.0.0
network 10.0.0.0
no auto-summary
配置BGP：
router bgp 1
bgp router-id 1.1.1.1
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
network 2.2.2.2 mask 255.255.255.255 backdoor
network 4.4.4.4 mask 255.255.255.255 backdoor
network 11.1.1.1 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 23
neighbor 2.2.2.2 ebgp-multihop 2
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 23
neighbor 4.4.4.4 ebgp-multihop 2
neighbor 4.4.4.4 update-source Loopback0
R2
router bgp 23
bgp router-id 2.2.2.2
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255 backdoor
network 2.2.2.2 mask 255.255.255.255
network 22.2.2.2 mask 255.255.255.255
neighbor 1.1.1.1 remote-as 1
neighbor 1.1.1.1 ebgp-multihop 2
neighbor 1.1.1.1 update-source Loopback0
neighbor 4.4.4.4 remote-as 23
neighbor 4.4.4.4 update-source Loopback0
R4
router bgp 23
bgp router-id 4.4.4.4
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255 backdoor
network 4.4.4.4 mask 255.255.255.255
network 44.4.4.4 mask 255.255.255.255
neighbor 1.1.1.1 remote-as 1
neighbor 1.1.1.1 ebgp-multihop 2
neighbor 1.1.1.1 update-source Loopback0
neighbor 2.2.2.2 remote-as 23
neighbor 2.2.2.2 update-source Loopback0
查看R1路由表:origin 为i，表示从IGP 学来的路由。
R1#sh ip bgp
BGP table version is 5, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid,> 最好,我——内部,,
,,,,,,,r RIB-failure,陈旧,米多路径,b backup-path, f RT-Filter,
,,,,,,,additional-path x best-external, c RIB-compressed,,
RPKI验证码:V有效,无效,N没有找到
,,,网络,,,,下一跳,,,,重量,度量LocPrf路径
, r,2.2.2.2/32,,,4.4.4.4,,,,,,,,,,,,,,,,23我
0, r>,,,,,,,,,2.2.2.2,,,,,,,,,0,,,,,23我0
, r,4.4.4.4/32,,,4.4.4.4,,,,,,,,,0,,,,,23我0
, r>,,,,,,,,,2.2.2.2,,,,,,,,,,,,,,,,0 23我
,
查看22.2.2.2 44.4.4.4的路由表:
R1 # sh ip边界网关协议22.2.2.2
22.2.2.2/32边界网关协议路由表条目,第4版
道路:(最好2,# 2,表默认)
,广告update-groups:
,,,18,,,
,刷新时代1
,23日
,,4.4.4.4(指标1)从4.4.4.4 (4.4.4.4)
,,,100年localpref有效,外部
,,,rx pathid: 0, tx pathid: 0
,刷新时代1
,23日
,,2.2.2.2(指标1)从2.2.2.2 (2.2.2.2)
,,,度量0 localpref 100年有效,外部,最好
,,,rx pathid: 0, tx pathid: 0 x0
R1 # sh ip边界网关协议44.4.4.4
44.4.4.4/32边界网关协议路由表条目,版本5
道路:(最好2,# 2,表默认)
,广告update-groups:
,,,18,,null
