RE: Maximum-path ibgp

I believe that's right in case of normal BGP.

Date: Wed, 31 Mar 2010 23:22:14 +0530
Subject: Re: Maximum-path ibgp
From: jckdaniels12_at_gmail.com
To: muzammil_mukhtar_at_hotmail.com
CC: naman.prep_at_gmail.com; ccielab_at_groupstudy.com

if it was BGP IPV4 then will it have imported routes from all 4 RR for same
prefix by default ?

On Wed, Mar 31, 2010 at 11:15 PM, Muzammil Mukhtar
<muzammil_mukhtar_at_hotmail.com> wrote:

> so import has to be configured under VPNV4 session of bgp <<<<<< this will
> bring update from diff RR in BGP table only and not in RIB.....
>
That's right

> But otherwise also all updates from all BGP peers (RR) should be their in
> BGP table as per ibgp behaviour.....route learnt frrom RR server is
> installed in BGP table >>>>>>>

It doesn't work this way in in MP-BGP situation, routes get imported from RR
that has the lower loopback id, PE will not import the routes from all RR for
same prefix pointing to same next-hop.

...Muhammad

> Date: Wed, 31 Mar 2010 22:54:48 +0530

> Subject: Re: Maximum-path ibgp
> From: jckdaniels12_at_gmail.com
> To: muzammil_mukhtar_at_hotmail.com
> CC: naman.prep_at_gmail.com; ccielab_at_groupstudy.com
>
> so import has to be configured under VPNV4 session of bgp <<<<<< this will
> bring update from diff RR in BGP table only and not in RIB.....
>
> But otherwise also all updates from all BGP peers (RR) should be their in
> BGP table as per ibgp behaviour.....route learnt frrom RR server is
> installed in BGP table >>>>>>>is their any clause of cluster-id in this
case
> for RR???
>
> On Wed, Mar 31, 2010 at 10:48 PM, Muzammil Mukhtar <
> muzammil_mukhtar_at_hotmail.com> wrote:
>
> > You got it, except, route update will not be in BGP table. BGP table will
> > show the import from only one RR, if you do the "import command" than it
> > will install all of them in BGP table.
> >
> > From BGP to RIB, it is a different selection mechanism based on BGP
> > attirbutes and whether you've iBGP multipath, ibgp unequal cost..etc.
> >
> >
> >
> > ------------------------------
> > Date: Wed, 31 Mar 2010 22:45:23 +0530
> >
> > Subject: Re: Maximum-path ibgp
> > From: jckdaniels12_at_gmail.com
> > To: muzammil_mukhtar_at_hotmail.com
> > CC: naman.prep_at_gmail.com; ccielab_at_groupstudy.com
> >
> > so you mean if I have topology with PE1 advertising 1.1.1.0/24
> >
> > PE1 is peering with 4 RR (VPNV4).....Route update will be their in BGP
> > table from all RR ( 4 RR's).....but I'll install only one ...
> >
> > If I use import comand it will insall all updates from 4 RR in routing
> > table <<<<<
> >
> >
> >
> >
> > On Wed, Mar 31, 2010 at 10:26 PM, Muzammil Mukhtar <
> > muzammil_mukhtar_at_hotmail.com> wrote:
> >
> > What tends to happen is let's say you've 4 RR and your P,PE routers
imports
> > routes from them but only one RR gets elected out of the 4 RR but if you
> > want to import routes from all of these RR than you choose the command
> > Import.
> >
> > > Date: Wed, 31 Mar 2010 21:01:34 +0530
> >
> > > Subject: Re: Maximum-path ibgp
> > > From: jckdaniels12_at_gmail.com
> > > To: muzammil_mukhtar_at_hotmail.com
> > > CC: naman.prep_at_gmail.com; ccielab_at_groupstudy.com
> > >
> > > requisest you to please explain in detail you were talking about RR
> > >
> > > On Wed, Mar 31, 2010 at 8:27 PM, Muzammil Mukhtar <
> > > muzammil_mukhtar_at_hotmail.com> wrote:
> > >
> > > > It will, that's the default behaviour of maximum-path, whatever
routes
> > > > marked as mutlipath in the BGP table will be insterted into the
routing
> > > > table.
> > > >
> > > >
> > > > > Date: Wed, 31 Mar 2010 20:11:21 +0530
> > > > > Subject: Re: Maximum-path ibgp
> > > > > From: jckdaniels12_at_gmail.com
> > > > > To: muzammil_mukhtar_at_hotmail.com
> > > > > CC: naman.prep_at_gmail.com; ccielab_at_groupstudy.com
> > > >
> > > > >
> > > > > Hi,
> > > > >
> > > > > but if maximum path is configured and next hop are 2 diffrent PE ,
so
> > > > wont
> > > > > it install both next hops in routing table if MXIMUM-path ibgp is
> > > > > configured.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > On Wed, Mar 31, 2010 at 7:29 PM, Muzammil Mukhtar <
> > > > > muzammil_mukhtar_at_hotmail.com> wrote:
> > > > >
> > > > > > Hello,
> > > > > >
> > > > > >
> > > > > >
> > > > > > The main purpose of this to improve the convergence time if
you've
> > > > multiple
> > > > > > route reflectors and the next hop is the same.
> > > > > >
> > > > > >
> > > > > >
> > > > > > For your setup, it may not make a difference as you are only
> > learning
> > > > the
> > > > > > prefix from two PEs, this feature is usually used where you've
> > multiple
> > > > > > Route-reflectors where route is only imported from the RR with
the
> > > > lower
> > > > > > loopback.
> > > > > >
> > > > > >
> > > > > >
> > > > > > ...Muhammad
> > > > > >
> > > > > >
> > > > > >
> > > > > > > Date: Wed, 31 Mar 2010 00:14:49 -0700
> > > > > > > Subject: Maximum-path ibgp
> > > > > > > From: naman.prep_at_gmail.com
> > > > > > > To: ccielab_at_groupstudy.com
> > > > > > >
> > > > > > > Hi,
> > > > > > >
> > > > > > > I need to understand the difference between normal maximum-path
> > ibgp
> > > > and
> > > > > > > maximum-path ibgp import. Now suppose if a PE is getting a same
> > route
> > > > > > from
> > > > > > 2
> > > > > > > different PE via a ibgp VPNv4 session.
> > > > > > >
> > > > > > > So if maximum-path ibgp is configured in that address-family it
> > will
> > > > put
> > > > > > 2
> > > > > > > routes in the VRF routing table. So what difference will it
make
> > if i
> > > > > > > configure import keyword along with this command.
> > > > > > >
> > > > > > > thanks
> > > > > > >
> > > > > > >
> > > > > > > Blogs and organic groups at http://www.ccie.net
> > > > > > >
> > > > > > >
> > > >
Received on Wed Mar 31 2010 - 17:53:52 ART