50、BGP配置实验之社团属性community

1、社团属性community解析

BGP社团属性community：

可开启：BGP社团属性community为可选属性，默认不识别。可通过命令开启：neighbor x.x.x.x send-community

传递性：BGP社团属性community只在邻居有效，邻居的邻居不再有效，想要传递到邻居的邻居需配置neighbor x.x.x.x send-community

修改BGP社团属性community步骤：

ip prefix-list 1 permit 1.1.1.0/24

route-map COM permit 10

 match ip address prefix-list 1

 set community no-advertise 不传给BGP邻居

 set community no-export不传出大AS

 set community local-AS 不传出小AS

route-map COM permit 20

router bgp 1

 neighbor 12.1.1.2 send-community

 neighbor 12.1.1.2 route-map COM out

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

 neighbor 12.1.1.2 send-community

 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

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

 neighbor 3.3.3.3 send-community

 no auto-summary

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

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

 neighbor 4.4.4.4 send-community 

 no auto-summary

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

interface Serial0/1

 ip address 45.1.1.4 255.255.255.0

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

 network 45.1.1.0 0.0.0.255 area 0

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

 neighbor 5.5.5.5 remote-as 64513

 neighbor 5.5.5.5 update-source Loopback0

 neighbor 5.5.5.5 send-community 

 no auto-summary

R5配置

interface Loopback0

 ip address 5.5.5.5 255.255.255.0

interface Serial0/0

 ip address 56.1.1.5 255.255.255.0

interface Serial0/1

 ip address 45.1.1.5 255.255.255.0

router ospf 110

 router-id 5.5.5.5

 network 5.5.5.0 0.0.0.255 area 0

 network 45.1.1.0 0.0.0.255 area 0

router bgp 64513

 no synchronization

 bgp router-id 5.5.5.5

 bgp confederation identifier 2

 neighbor 4.4.4.4 remote-as 64513

 neighbor 4.4.4.4 update-source Loopback0

 neighbor 56.1.1.6 remote-as 6

 neighbor 56.1.1.6 send-community 

 no auto-summary

R6配置

interface Loopback0

 ip address 6.6.6.6 255.255.255.0

interface Serial0/0

 ip address 56.1.1.6 255.255.255.0

router bgp 6

 no synchronization

 bgp router-id 6.6.6.6

 neighbor 56.1.1.5 remote-as 2

 no auto-summary

4、社团属性验证

ip prefix-list 1 seq 5 permit 1.1.1.0/24

route-map COM permit 10

 match ip address prefix-list 1

 set community no-advertise

route-map COM permit 20

router bgp 1

 neighbor 12.1.1.2 send-community

 neighbor 12.1.1.2 route-map COM out

ip prefix-list 1 seq 5 permit 1.1.1.0/24

route-map COM permit 10

 match ip address prefix-list 1

 set community no-export

route-map COM permit 20

router bgp 1

 neighbor 12.1.1.2 send-community

 neighbor 12.1.1.2 route-map COM out

ip prefix-list 1 seq 5 permit 1.1.1.0/24

route-map COM permit 10

 match ip address prefix-list 1

 set community local-AS

route-map COM permit 20

router bgp 1

 neighbor 12.1.1.2 send-community

 neighbor 12.1.1.2 route-map COM out