49、BGP配置实验之联邦
1、联邦解析
联邦工作原理：在AS内部手动划分多个私有AS（联邦中的私有AS好不增加AS-PATH的路径长度）
配置步骤：
第一步：router bgp 小AS号（私有AS号）
第二步：声明所在大AS号
第三步：小AS号之间互指peer
2、实验拓扑
3、基础配置
R1配置
interface Loopback0
ip address 1.1.1.1 255.255.255.0
interface Serial0/0
ip address 12.1.1.1 255.255.255.0
router bgp 1
no synchronization
bgp router-id 1.1.1.1
network 1.1.1.0 mask 255.255.255.0
neighbor 12.1.1.2 remote-as 2
no auto-summary
R2配置
interface Loopback0
ip address 2.2.2.2 255.255.255.0
interface Serial0/0
ip address 12.1.1.2 255.255.255.0
interface Serial0/1
ip address 23.1.1.2 255.255.255.0
router ospf 110
router-id 2.2.2.2
network 2.2.2.0 0.0.0.255 area 0
network 23.1.1.0 0.0.0.255 area 0
R3配置
interface Loopback0
ip address 3.3.3.3 255.255.255.0
interface Serial0/0
ip address 34.1.1.3 255.255.255.0
interface Serial0/1
ip address 23.1.1.3 255.255.255.0
router ospf 110
router-id 3.3.3.3
network 3.3.3.0 0.0.0.255 area 0
network 23.1.1.0 0.0.0.255 area 0
network 34.1.1.0 0.0.0.255 area 0
R4配置
interface Loopback0
ip address 4.4.4.4 255.255.255.0
interface Serial0/0
ip address 34.1.1.4 255.255.255.0
router ospf 110
router-id 4.4.4.4
network 4.4.4.0 0.0.0.255 area 0
network 34.1.1.0 0.0.0.255 area 0
4、配置邻邦解决水平分割
R2配置
router bgp 64512
no synchronization
bgp router-id 2.2.2.2
bgp confederation identifier 2
neighbor 3.3.3.3 remote-as 64512
neighbor 3.3.3.3 update-source Loopback0
neighbor 3.3.3.3 next-hop-self
neighbor 12.1.1.1 remote-as 1
no auto-summary
R3配置
router bgp 64512
no synchronization
bgp router-id 3.3.3.3
bgp confederation identifier 2
bgp confederation peers 64513
neighbor 2.2.2.2 remote-as 64512
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 64513
neighbor 4.4.4.4 ebgp-multihop 255
neighbor 4.4.4.4 update-source Loopback0
no auto-summary
R4配置
router bgp 64513
no synchronization
bgp router-id 4.4.4.4
bgp confederation identifier 2
bgp confederation peers 64512
neighbor 3.3.3.3 remote-as 64512
neighbor 3.3.3.3 ebgp-multihop 255
neighbor 3.3.3.3 update-source Loopback0
no auto-summary
