NLR PacketNet BGP Communities
BGP communities we set on inbound routes. These are routes that other networks connected
to NLR should be able to match on:
BGP communities set by BGP peers. These are routes NLR will take action on when received from an extenal peering
19401:911 – Blackhole
19401:600 – Sets NLR local pref to 600
19401:400 – Sets NLR local pref to 400
19401:200 – Sets NLR local pref to 200
19401:1000-1999 – NLR internal
Typically set to 1000
19401:2000-3999 – NLR Members
Typically set to 2000
Typical local pref 500
Other values reserved for future use
19401:4000-4999 – R&E Peers
Typically set to 4000
Typical local pref 300
Other values reserved for future use
19401:5000-6999 – International Peers
Typically set to 5000
Typical local pref 300
Other values reserved for future use
19401:7000-7999 – US Government and Federal Labs
Typically set to 7000
Typical local pref 300
Other values reserved for future use
19401:8000-8999 – Commercial Labs/Partners
Typically set to 8000
Typical local pref 300
Other values reserved for future use
19401:9000-9999 – Commodity Peers
Typically set to 9000
Typical local pref 100
Other values reserved for future use
19401:10000-10999 – Special Event Peerings (SC, iGrid, meetings)
Typically set to 10000
Typical local pref 1000
Other values reserved for future use
Applying BGP Community string with sample configuration
1. Get the latest BGP community string from your ISP/upstream provider or check www.ShowipBGP.com.
2. Pick the best BGP community string for your traffic shaping plan (mainly incoming traffic). Most of ISPs are providing community string with local preference and AS prepending option. Cannot tell which one is better than the other. It will depend on your global traffic shaping plan.
3. Follow the below commands ( Cisco only )
The below Sample configuration will tag the 10.0.0.0/24 route with 19401:200 and will not tag any other routes.
router#config t
router(config)#ip bgp-community new-format
router(config)#access-list 10 permit 10.0.0.0 0.0.0.255
router(config)#access-list 10 deny any
router(config)#route-map to-AS19401 permit 10
router(config-route-map)#match ip address 10
router(config-route-map)#set community 19401:200 <—— using Local Preference
router(config-route-map)#route-map to-AS19401 permit 20
router(config-route-map)#exit
router(config)#router bgp [xxxx] <—————————- xxxx = customer’s ASN
router(config-router)#neighbor x.x.x.x send-community
router(config-router)#neighbor x.x.x.x route-map to-AS19401 out
router(config-router)#exit
router(config)#exit
router#copy running-config startup-config
4. And then, go to www.RouteServer.org and pick one of route server on the map to see your announcement. If you are using AS prepending option, you will see your AS prepends on route servers. Sometime you might not see your route with particular ISP path.
In most of case it might not be any routing problem, just the route path was dropped at somewhere by BGP best path selection scheme. Try Oregon route server, if you can see your route. The Oregon route server is providing many possible and available paths between BGP speakers and neighbors.
If you don’t see your route on there? check other route servers and also check your
BGP configuration. You might need to contact your upstream provider to check what they are learning BGP route from you.