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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: bgp as-path info
IIRC, They will advertise your specifics if you attach a community of 7018:20 to the route as you send it to them. Otherwise they aggregate all of the routes in the 12/8. -Ejay -----Original Message----- From: Austad, Jay [mailto:[email protected]] Sent: Tuesday, September 02, 2003 1:19 PM To: 'Jack Bates'; Austad, Jay Cc: [email protected] Subject: RE: bgp as-path info Actually, it looks like this is what they are doing. I've already put a call in with them. > -----Original Message----- > From: Jack Bates [mailto:[email protected]] > Sent: Tuesday, September 02, 2003 1:17 PM > To: Austad, Jay > Cc: [email protected] > Subject: Re: bgp as-path info > > > If you look closely, they are probably not just stripping > your AS. They > are probably aggregating your network. One provider that I am > aware of > that does this is AT&T. Since your advertisements out the > other network > will be more specific, traffic will only come through them. If the > networks are the same size, then traffic will most likely > come through > your first provider due to AS path counts. > > Usually, you have to request that your more specific routes > be allowed > out due to multi-homing. In the case of AT&T, they have a > community that > you must send with the route to have it sent beyond their > local network. > It's really just a matter of default preference on the part of your > provider. Some default to advertise more specific while > others default > to advertising their aggregates. The latter is used most > commonly when a > provider does a lot of BGP peering that is not multi-homed. > It's not a > bad policy when it comes to looking at the BGP tables. > > -Jack > > Austad, Jay wrote: > > > I just brought up a BGP session with one of my providers, > they are stripping > > our AS as it leaves their network, so it looks like the > route is originating > > from their network. I have another provider that I will be > bringing up BGP > > with later this week. Once I bring up the other provider, I will be > > advertising several networks out both of them. > > > > Is this as-path stripping going to cause issues? Does it > matter either way? > > > > -jay > > >
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