配置命令：

R1：

access-list 1 permit 1.1.1.1  //匹配1.1.1.1路由

route-map community permit 10

match ip address 1  //匹配ACL 1的路由

set community no-export  //添加社團屬性值為不通告出本AS

router bgp 1

neighbor 12.1.1.2 send-community  //告訴鄰居識別社團屬性

neighbor 12.1.1.2 route-map community out  //調用在EBGP鄰居出方向

R2:

Router bgp 64523

Neighbor 3.3.3.3 send-community

R3：

Router bgp 64523

Neighbor 4.4.4.4 send-community

查看社團屬性