[dn42] BGP communities for route origin

tombii admin at tombii-dn42.com
Tue Dec 1 16:59:08 UTC 2015

Dear all,

I am interested in seeing where a route was learned (BGP ingress) for 
routing purposes. One way to implement and share this information is 
through the use of BGP communities.

I'm proposing to use the dn42 BGP community 64511 and using the 
following values for the different parts of the world:

Region			Value
Europe			41
North America-E		42
North America-C		43
North America-W		44
Central America		45
South America-E		46
South America-W		47
Africa-N (above Sahara)	48
Africa-S (below Sahara)	49
Asia-S IN PK BD 	50
Asia-E JP CN KR		52
Pacific			53

As an example, a route learned in Europe will have the community 
(64511,41) and a route learned in Singapore would have (64511,51). The 
regions were chosen based on peering, for example latency within Europe 
is usually low enough not to warrant a division into further sub-groups.

I'm looking at implementing this now and to start to base routing 
decisions on this as soon as I finish a suitable bgp.local_pref 
calculation. I'll be experimenting with this further this week.

All comments are welcome but based on this, I'd like to reserve 
(64511,41) to (64511,60) for marking route origins.

Thanks to chrismoos for valuable input.

Best regards

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