R6 ----- R3 ------ R5
R6 的AS 65530
R3的AS 1
R5的AS 2
聚合172.16.0.0/24到172.16.3.0/24
R6的配置
interface Serial1
ip address 172.17.1.2 255.255.255.0
!
router bgp 65530
bgp log-neighbor-changes
neighbor 172.17.1.1 remote-as 1
!
R3的配置
interface Serial0
ip address 10.1.1.1 255.255.255.0
no ip route-cache
no ip mroute-cache
clockrate 500000
!
interface Serial1
ip address 172.17.1.1 255.255.255.0
no ip route-cache
no ip mroute-cache
clockrate 500000
!
interface BRI0
no ip address
no ip route-cache
no ip mroute-cache
shutdown
!
router bgp 1
bgp log-neighbor-changes
aggregate-address 172.16.0.0 255.255.252.0
neighbor 10.1.1.2 remote-as 2
neighbor 172.17.1.2 remote-as 65530
!
R5的配置
!
interface Loopback0
ip address 172.16.0.1 255.255.255.0
!
interface Loopback1
ip address 172.16.1.1 255.255.255.0
!
interface Loopback2
ip address 172.16.2.1 255.255.255.0
!
interface Loopback3
ip address 172.16.3.1 255.255.255.0
!
interface Ethernet0
no ip address
no ip mroute-cache
shutdown
no cdp enable
!
interface Serial0
ip address 10.1.1.2 255.255.255.0
no ip mroute-cache
!
!
router bgp 2
bgp log-neighbor-changes
network 172.16.0.0 mask 255.255.255.0
network 172.16.1.0 mask 255.255.255.0
network 172.16.2.0 mask 255.255.255.0
network 172.16.3.0 mask 255.255.255.0
neighbor 10.1.1.1 remote-as 1
在R3上使用sh ip bgp
R3#sh ip bgp
BGP table version is 6, local router ID is 192.168.0.80
Status codes: s suppressed, d damped, h history, * valid, best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* 172.16.0.0/24 10.1.1.2 0 0 2 i
* 172.16.0.0/22 0.0.0.0 32768 i
* 172.16.1.0/24 10.1.1.2 0 0 2 i
* 172.16.2.0/24 10.1.1.2 0 0 2 i
* 172.16.3.0/24 10.1.1.2 0 0 2 i