From: Dave Humphrey (dave.humphrey@xxxxxxxxxx)
Date: Mon Dec 06 1999 - 10:37:32 GMT-3
Here's a good interview question. What's the difference between a packet
without ebgp multi-hop set and and one which includes it?
Dave
----- Original Message -----
From: Bill Wade <wwade@cisco.com>
To: Peter Van Oene <vantech@sympatico.ca>; <ccielab@groupstudy.com>
Sent: Monday, December 06, 1999 3:14 AM
Subject: Re: Re[2]: BGP Update-source
> With IBGP there is an IGP to get you to the loopback address which is not
directly atached. With EBGP, if you peer to a loopback, you need to use
ebgp-multihop.
>
> Bill
>
>
>
>
>
> At 12:44 AM 12/5/99 , Peter Van Oene wrote:
> >I'm certainly no expert in BGP, however whenever I use looback addresses
> >(which is whenever I use BGP) I always use the EBGP-Multi-hop statement.
> >Given that the two loopbacks are essentially a minimum of 2 hops away, I
> >would see that this command is relevant. How would the router
differentiate
> >it from any other network that was not directly connected?
> >
> >
> >
> >Peter Van Oene
> >Senior Systems Engineer
> >UNIS LUMIN Inc.
> >www.unislumin.com
> >Convergis Member Company
> >www.convergis.com
> >
> >----- Original Message -----
> >From: Stanislav Sinyagin <SSinyagin@mtu.ru>
> >To: Martin Bander <cisco103@hotmail.com>
> >Cc: <honsiong@hotmail.com>; <ccielab@groupstudy.com>
> >Sent: Sunday, December 05, 1999 11:14 AM
> >Subject: Re[2]: BGP Update-source
> >
> >
> >> Ebgp-multihop is not required at all in this scenario. Your bgp
> >> session is "Active" because one of your routers does not know how to
> >> reach the other's loopback. You should tell it by static or dynamic
> >> routing. And make sure that both point to each other's loopback and
> >> have update-src loopback, or both point to other's physical interface
> >> (and no updare-src at all).
> >>
> >> Regards,
> >> Stan
> >>
> >> Martin Bander <cisco103@hotmail.com> wrote:
> >> MB> Don't forget the ebgp-multihop comand, since r1's loopback
interface
> >is not
> >> MB> 'directly connected' to r2.
> >>
> >>
> >> MB> ----Original Message Follows----
> >> MB> From: "hon-siong chan" <honsiong@hotmail.com>
> >> MB> Reply-To: "hon-siong chan" <honsiong@hotmail.com>
> >> MB> To: ccielab@groupstudy.com
> >> MB> Subject: BGP Update-source
> >> MB> Date: Thu, 02 Dec 1999 20:28:02 PST
> >>
> >> MB> I followed Sam Halabi book on configuring a simple BGP peering by
> >pointing
> >> MB> to a loopback interface. Scenario is as simple as follows:
> >>
> >> MB> -----R1 --------R2
> >>
> >> MB> Where R1 has a loopback interface and both are in same AS. In R1,
> >command
> >> MB> as:
> >>
> >> MB> neighbor <R2> remote-as 100
> >> MB> neighbor <R2> update-source loopback 0
> >>
> >> MB> The peering can never be established since then. A "Sh ip bgp
neigh"
> >showed
> >> MB> "Active" status only?!
> >>
> >> MB> What's wrong?
> >>
> >> MB> Thanks in advance....
> >>
> >> MB> HonSiong
> >>
> >>
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