BGP communities

[omulete]

hy guys,

i know that here maybe it's not the ideal place to post this question, but on the cisco forum a don't find a better place :).

so :

we want to implement some bgp communities in our mpls backbone to help ebgp customers and to have in final a very consistent bgp policy. the idea is that we have a couple ideas, but we also search for ideas on other big providers web sites and we find a couple of things but ... we don't understand how they do. for example we saw that they use different bgp commnunities for Europa, North America and Asia. The question is : how they are able to separate from global prefixes the distinct prefixes for every region ?

[olorunloba]

Can you please expantiate on the problem?

[omulete]

the idea is how to differentiate the traffic ?

i receive the whole internet routes and i want to differentiate traffic : european traffic (ip prefixes for europa), north american traffic (ip prefixes for north america) and so on. on the iana i found the whole ip address space and how it is allocated.

[olorunloba]

I do not know how the big providers do it. But if you have the plan detailing who has which address, I should expect that you can create prefix list and use an inbound route-map to set the communities.

[maosa7578]

I can not imagine that all that the "big providers" are doing is vaguely identifying internet prefixes by region ( I could be wrong ).

My guess is that they probably have customers in those regions that they are trying to apply the BGP Policies to, in which case they are going to have documentation about specific customer prefixes in the regions.

My 2 cents worth.