Steve Bertrand wrote: >> BGP is the method. If for some reason someone or something says "BGP is >> not an option", that someone or something needs to be eliminated from >> the puzzle. I've done BGP with a fractional T1 customer, they can do it >> too. > > So, if I understand you right, this is what you would propose, assuming > that you were provider 'A', and it was your /24 you were assigning to > the OP: > > - 'A' routes a /24 to OP
'A' assigns a /24 to OP. Better if they don't static route it; let BGP do its thing. > - OP advertises the /24 to provider A and B via BGP with personal local > preferences in place > - A advertises it's aggregate including the /24 to the 'net A advertises its aggregate, and propagates OP's /24 announcement. > - B advertises the more specific /24 prefix to the 'net > - OP uses an ASN from the private range, which both A & B must agree to > honour Use a public ASN. That's what they're there for. > I'd really like to understand this, because I've never had to deal with > a situation where I've received a prefix from one ISP and needed to > multi-home with it. (I have my own ARIN prefix). > > Will the more specific /24 route advertised to the 'net by B not be the > preferred route at all times? If A propagates OP's announcement, it'll load dribble/share based on the rules of BGP. Fairly quick and easy; your routers don't care who provided the /24 and they don't care about the AS path once they've selected a path. We had a church do this...I probably spent more time explaining it to them AND to the other ISP than it would have taken to lab it up and test it. pt _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
