nanog mailing list archives
Re: AS prepending
From: David Gethings <davidg () pipex net>
Date: Fri, 8 Apr 2005 16:25:50 +0100
On Friday 08 April 2005 16:04, Philip Lavine wrote:
I am prepending my AS 3 times to the un-preferred ISP. Both ISP's are my peers. The un-preferred ISP claims the see my advertisement yet they do not add it to their routing table (suggests filtering??). They claim all the filtering they are doing is based on the networks I told them over the phone that I was using with that AS.
To answer your originial question: it is not "normal" to filter routers with the same AS prepended 3 times. However if the ISP chose such a policy they could do that. On this subject: When they say "do not add it to their routing table" do you know if they mean the BGP table or the IP table? i.e. if the ISP in question does a "sh ip bgp route <your prefix>" does it show in the list. Yet when they do a "sh ip route <your prefix>" it does not. If so then your ISP will be preferring a different route. Are you certain that the prefix filters this ISP is using - well sounds like they are using - are the same as the prefixes you are announcing? It could be that the prefix list is misconfigured. -- Cheers Dg
Current thread:
- AS prepending Philip Lavine (Apr 08)
- Re: AS prepending Patrick W Gilmore (Apr 08)
- Re: AS prepending Hank Nussbacher (Apr 09)
- Re: AS prepending Jon Lewis (Apr 08)
- <Possible follow-ups>
- Re: AS prepending christian . macnevin (Apr 08)
- Re: AS prepending Philip Lavine (Apr 08)
- Re: AS prepending David Gethings (Apr 08)
- Re: AS prepending Jon Lewis (Apr 08)
- Re: AS prepending Pete Templin (Apr 08)
- Re: AS prepending Philip Lavine (Apr 08)
- Re: AS prepending David Gethings (Apr 08)
- Re: AS prepending David Barak (Apr 08)
- Re: AS prepending Patrick W Gilmore (Apr 08)