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