BGP Community String for AboveNet Inc AS6461

Attention

This BGP Community string information might be outdated. Please contact  AboveNet Inc AS6461 to get more recent one. This BGP communites is ONLY for the customer who has BGP with  AboveNet Inc AS6461. www.ipbalance.com is not maintaining this BGP Community string.

 

Customers may set any of the following BGP communities in order to alter the default treatment of prefixes advertised to AboveNet.

6461:5000 suppress announcement to all peers
6461:5001 prepend once to all peers
6461:5002 prepend twice to all peers
6461:5003 prepend three times to all peers
6461:5060 set localpref inside AS6461 to 60 (transit-backup)
6461:5180 set localpref inside AS6461 to 180 (transit-depref)
6461:5220 set localpref inside AS6461 to 220 (transit-preferred)
6461:5990 Blackhole BGP community – All Sessions are enabled by Default.
65535:65281 (a.k.a. NO_EXPORT) do not announce to anyone


Whenever BGP communities are sent to customers they are translated into
one of three possible categories:

6461:5997 prefix was learned from a peer
6461:5998 prefix was learned from a customer
6461:5999 internal prefix

 

 

Applying BGP Community string with sample configuration

1. Get the latest BGP community string from your ISP/upstream provider or check www.ShowipBGP.com web site.

2. Pick the best BGP community string for your traffic shaping plan (mainly incoming traffic). Most of ISPs are providing BGP 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 [ISP AS]:120 or [ISP AS]:3 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-ISP] permit 10
router(config-route-map)#match ip address 10
router(config-route-map)#set community [ISP AS]:120 <—- using Local Preference

or

router(config-route-map)#set community [ISP AS]:3 <——- using AS prepending
router(config-route-map)#route-map [to-ISP] 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-ISP] 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.

 

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