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
