From: Dave Humphrey (dave.humphrey@xxxxxxxxxx)
Date: Mon Dec 06 1999 - 10:50:01 GMT-3
I've seen a couple of ways of doing this.
Within IBGP the IGP provides the connectivity and ebgp multi-hop is not an
option.
Within EBGP most companies I have worked with don't use multi-hop for
peering sessions unless they are lad balancing between multiple peers. In
this way the next hop will be the ip address of the router you are peering
with and the network that this is attached will be advertised back into your
own AS via the IGP normally via redistribution.
Alternatively I have seen ISP's who change the next hop of the route to be
that of the ASBR doing the peering, thus removing the requirement to
redistribute the external network into the IGP.
Dave
----- Original Message -----
From: Peter Van Oene <vantech@sympatico.ca>
To: <ccielab@groupstudy.com>
Sent: Sunday, December 05, 1999 5:44 AM
Subject: Re: Re[2]: BGP Update-source
> 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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