BGP Community String for Voyager GmbH Germany AS12732
BGP Communities Support Definitions for Customers
1. BGP Communities controlling Voyager GmbH Germany internal use of customer routes by means of local preference:
All customer routes announced will receive a default local preference of 900
BGP community set local effect preference 12732:10 10 below everything, least prefered 12732:90 90 below peers 12732:400 400 below peering & customer default 12732:800 800 below customer default 12732:950 950 above customer default
2. BGP Communities controlling AS path prepending for customer routes on egress:
BGP community effect 12732:1000 do not announce at BCIX 12732:1001 prepend one at BCIX 12732:1002 prepend two at BCIX
12732:2000 do not announce at FFM/DeCIX 12732:2001 prepend one at FFM/DeCIX 12732:2002 prepend two at FFM/DeCIX
12732:3000 do not announce at DUS/ECIX 12732:3001 prepend one at DUS/ECIX 12732:3002 prepend two at DUS/ECIX
3. BGP Communities tagging the source of routes
12732:10000 peer route, learned at DeCIX 12732:10001 peer route, learned at BCIX 12732:10002 peer route, learned at ECIX 12732:10003 peer route, learned at WorkerX 12732:10008 normal path 12732:10009 backup path
12732:10021 peer route, learned in Duesseldorf 12732:10030 peer route, learned in Berlin 12732:10034 peer route, learned in Leipzig 12732:10040 peer route, learned in Hamburg 12732:10089 peer route, learned in Frankfurt
4. Others
Applied Route Flap Damping Policy conformant to RIPE-178 Peerings (IPv4 & IPv6) are welcome ;-)
Applying BGP Community string with sample configuration
1. Get the latest BGP community string from your ISP/upstream provider or check new.CiscoNET.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
4. And then, go to www.CiscoNET.com 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.
Routing 
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