Define a BGP4+ Extended Community

You must define a BGP4 extended community filter before you can apply the filter.

1. Access global configuration mode.
   

   device# configure terminal

2. Specify an extended community list instance.
   

   device(config)# ip extcommunity-list standard mylist permit soo 123:2

   This example specifies the extended community list titled mylist and allows site of origin (SOO) from network 2 in autonomous system 123.

   

   Note

   The ip-extcommunity-list command supports a range of extended instances from 100 through 500, beyond the standard range of 1 through 99.
3. Create an inbound route map instance and enter route-map configuration mode.
   

   device(config)# route-map extComRmap permit 10

   This example creates the extComRmap route map that allows a matching pattern, with an instance ID of 10.
4. Configure the route map to match the extended community list.
   

   device(config-route-map-extComRmap/permit/10)# match extcommunity mylist

5. Exit route-map configuration mode.
   

   device(config-route-map-extComRmap/permit/10)# exit

6. Create an outbound route map instance and enter route-map configuration mode.
   

   device(config)# route-map sendExtComRmap permit 10

   This example creates the sendExtComRmap route map that allows a matching pattern, with an instance ID of 10.
7. Specify the route target (RT) extended community attribute.
   

   device(config-route-map-sendExtComRmap/permit/10)# set extcommunity rt 3:3

   This example specifies the set extcommunity command, the rt keyword, and the extcommunityvalue variable.
8. Set the extended community attribute in the route-map instance.
   

   device(config-route-map-sendExtComRmap/permit/10)# set extcommunity soo 2:2

   This example specifies the SOO extended community attribute with the soo keyword and the extcommunityvalue variable.

Example

The following example summarizes the commands in this procedure.

device# configure terminal
device(config)# ip extcommunity-list standard mylist permit soo 123:2
device(config)# route-map extComRmap permit 10
device(config-route-map-extComRmap/permit/10)# match extcommunity mylist
device(config-route-map-extComRmap/permit/10)# exit
device(config)# route-map sendExtComRmap permit 10
device(config-route-map-sendExtComRmap/permit/10)# set extcommunity rt 3:3
device(config-route-map-sendExtComRmap/permit/10)# set extcommunity soo 2:2