From: Paglia, John (USPC.PCT.Hopewell) (JPaglia@NA2.US.ML.com)
Date: Wed Oct 16 2002 - 20:43:55 GMT-3
Thanks for the reply. Actually, I am not having a problem. I was just
wondering about something someone told me. I never have configured 'ebgp-mu'
for connected neighbors, but this person said 'you need it if using
'update-source loop 0' because loop 0 isn't directly connected to the
neighbor.'
I just wanted to know if anyone else has heard of such madness. I've never
configured BGP like this and it has never been a problem.
Thanks,
John
> -----Original Message-----
> From: Rem [SMTP:rem@digdomsol.com]
> Sent: Wednesday, October 16, 2002 7:27 PM
> To: Paglia, John (USPC.PCT.Hopewell)
> Subject: RE: EBGP Multihop's necessity with loopback addresses
>
> Are you running an igp between those neighbors?
>
> Where ebgp-multihop comes into play is between neighbors that are not
> directly connected and run only ebgp between them, ie your 2 loopback
> interfaces. if you run a trace between these 2 while running only ebgp you
> will see that they will not be able to perform a tcp connection, that is
> because the loopbacks do not know how to get to the remote side. if an igp
> is running between your serial connection then the route is established
> and
> the tcp connection can occur.
>
> try removing any internal routing protocol from your tables and see if it
> drops the connection. it has been my experience that this is currently the
> case and i know from experience that it has been a problem. watch out for
> it
> on the test when your start redistributing and the igp route goes away and
> all of a sudden your bgp drop also. its a nasty little thing if you don't
> see it coming.
>
> hth
> Ross
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Paglia, John (USPC.PCT.Hopewell)
> Sent: Wednesday, October 16, 2002 1:01 PM
> To: 'ccielab@groupstudy.com'
> Subject: EBGP Multihop's necessity with loopback addresses
>
>
> I recently heard that if you are establishing your BGP neighbors using
> 'update source loopback 0', you should also use the 'ebgp-mu' cmd, even if
> the neighbors are directly connected...the reason being that your loopback
> is NOT directly connected to the neighbor. However, in my experiments I
> have
> never done this for neighbors that are directly connected, yet have
> established peerings successfully.
>
> Is there validity to this statement, and if so, under which circumstances
> is
> it absolutely vital, other than the 'non-physically or nbma topology'
> scenarios??? Something tells me that this may be an older IOS issue or
> something like that.
>
> John
This archive was generated by hypermail 2.1.4 : Tue Nov 05 2002 - 08:35:48 GMT-3