From: Treptow, Georg (gxtrept@xxxxxxxxx)
Date: Tue Jun 04 2002 - 14:06:21 GMT-3
I believe the the ttl for IBGP is automatically set to 255 as not every IGP
router must speak iBGP. The key is to advertise the loopback address within
the IGP so the BGP router knows how to get to it. Someone correct me if I am
wrong....
Georg
-----Original Message-----
From: Edward Monk [mailto:emonk@att.net]
Sent: Tuesday, June 04, 2002 10:16 AM
To: 'Paglia, John (USPC.PCT.Hopewell)'; 'Logan, Harold'; 'Annu Roopa';
ccielab@groupstudy.com
Subject: RE: BGP Update-Source issue
I tested and the update-source loopback command had to be used in all
cases where you point to a loopback address. Regardless of whether you
have an eBGP or an iBGP peer relationship. eBGP multihop is added to get
around the TTL=1 issue of BGP when working with an eBGP peer.
So the story is:
Add neighbor x.x.x.x eBGP-multihop 2<-- or higher if you want to eBGP
peers when going to a loopback.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Paglia, John (USPC.PCT.Hopewell)
Sent: Monday, June 03, 2002 2:33 PM
To: 'Logan, Harold'; Annu Roopa; emonk@att.net; ccielab@groupstudy.com
Subject: RE: BGP Update-Source issue
I believe you are correct. You have to use the loop in the neighbor
statement for update-source loop 0 to be effective.
And you need to use EBGP-Multihop when peering ebgp peers via loopback
addresses.
Pags
> -----Original Message-----
> From: Logan, Harold [SMTP:loganh@mccfl.edu]
> Sent: Tuesday, May 28, 2002 5:25 PM
> To: Annu Roopa; JPaglia@NA2.US.ML.com; emonk@att.net;
> ccielab@groupstudy.com
> Subject: RE: BGP Update-Source issue
>
> To get a BGP session to work using a loopback as the update source,
I've
> had to use the remote router's loopback IP in the neighbor command.
That
> is, if you use update-source Lo0 on a router, then that router's BGP
peer
> needs to use the IP address of the Lo0 interface in its neighbor
command.
> Anyone else run into that?
>
> Hal
>
> > -----Original Message-----
> > From: Annu Roopa [mailto:annu_roopa@yahoo.com]
> > Sent: Tuesday, May 28, 2002 5:16 PM
> > To: JPaglia@NA2.US.ML.com; Logan, Harold; emonk@att.net;
> > ccielab@groupstudy.com
> > Subject: RE:BGP Update-Source issue
> >
> >
> > Group,
> >
> > This is my understanding.Whenever u create a EBGP peer
> > u generally do it with the neighbors peer address
> > which is the next hop serial link IP address. Now
> > since the peer relationship is being formed using ur
> > Loopback address u use "update-source" .U will use the
> > same command irespective of what interface u
> > use..other than serial IP.
> >
> > Whenever u dont form a peer/neighbor relationship
> > using point-point link (with TTL=1)... it could be any
> > other IP address on the neighbor u need to use the
> > "ebgp-multihop". This works only with EBGP as i know.
> >
> > Thus u may both being used togethter most of the
> > times.
> > HTH.
> >
> > Annu
> >
> >
> > >From: "Paglia, John (USPC.PCT.Hopewell)"
> > <JPaglia@NA2.US.ML.com>
> > >Reply-To: "Paglia, John (USPC.PCT.Hopewell)"
> > <JPaglia@NA2.US.ML.com>
> > >To: "'Logan, Harold'" <loganh@mccfl.edu>, "Edward
> > Monk" <emonk@att.net>, ccielab@groupstudy.com
> > >Subject: RE: BGP Update-Source issue
> > >Date: Tue, 28 May 2002 16:28:56 -0400
> > >
> > >Isn't Update Source used only when configuring within
> > a single AS? What I
> > >understood from my reading (although I may have been
> > whacked from lack of
> > >sleep at the time) is that Update Source will have no
> > effect when
> > >configuring with reference to a router in another AS.
> > I do know that
> > >ebgp-multihop is necessary when pointint ot a
> > loopback from another AS.
> > >
> > >Am I way off on this one?
> > >
> > > > -----Original Message-----
> > > > From: Logan, Harold [SMTP:loganh@mccfl.edu]
> > > > Sent: Tuesday, May 28, 2002 12:50 PM
> > > > To: Edward Monk; ccielab@groupstudy.com
> > > > Subject: RE: BGP Update-Source issue
> > > >
> > > > When you set that up, what's the output of your
> > show ip bgp neighbors?
> > > > Remember, bgp networks won't show up in your
> > routing tables unless you
> > > > redistribute into bgp or use the network command.
> > If you've done that
> > > > already there are several other possibilities,
> > would you mind posting the
> > > > configs?
> > > >
> > > > > -----Original Message-----
> > > > > From: Edward Monk [mailto:emonk@att.net]
> > > > > Sent: Tuesday, May 28, 2002 12:16 PM
> > > > > To: ccielab@groupstudy.com
> > > > > Subject: BGP Update-Source issue
> > > > >
> > > > >
> > > > > I am trying to use loopbacks as the
> > update-source with BGP and cannot
> > > > > get the following to work. I have rebooted
> > etc....
> > > > >
> > > > >
> > > > >
> > > > > Both routers can ping the others loopback
> > address. Anyone
> > > > > have any idea
> > > > > what is wrong?
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > R8:
> > > > >
> > > > >
> > > > >
> > > > > router bgp 500
> > > > >
> > > > > bgp log-neighbor-changes
> > > > >
> > > > > neighbor 10.10.10.7 remote-as 400
> > > > >
> > > > > neighbor 10.10.10.7 update-source Loopback0
> > > > >
> > > > >
> > > > >
> > > > > R7:
> > > > >
> > > > >
> > > > >
> > > > > router bgp 400
> > > > >
> > > > > bgp log-neighbor-changes
> > > > >
> > > > > neighbor 10.10.10.8 remote-as 500
> > > > >
> > > > > neighbor 10.10.10.8 update-source Loopback0
> >
> >
> > =====
> > Thanks in advance for ur time and replies.
> > Annu.
> >
This archive was generated by hypermail 2.1.4 : Tue Jul 02 2002 - 08:12:23 GMT-3