From: Paglia, John (USPC.PCT.Hopewell) (JPaglia@NA2.US.ML.com)
Date: Tue Oct 15 2002 - 18:01:44 GMT-3
Always prepare for the worst with this lab test, because it IS the worst!!!!
I do every screnario with sync on, which was one of the best pieces of
advice I got from this list because it really gets your creative juices
flowing with regard to BGP.
Leave it on, work it out. And of course after (and only AFTER) you bruised
your forehead from smacking it against a wall numerous times, consult your
good friends at groupstudy.
John
> -----Original Message-----
> From: Joe Martin [SMTP:jmartin@capitalpremium.net]
> Sent: Tuesday, October 15, 2002 4:44 PM
> To: Peter van Oene; ccielab@groupstudy.com
> Subject: RE: Help with Local Preference
>
> That would be nice, and I know that's what we do in the real world. But I
> can just about guarantee that they are not going to let you turn off sync
> on
> the lab.
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Peter van Oene
> Sent: Tuesday, October 15, 2002 2:01 PM
> To: ccielab@groupstudy.com
> Cc: ccielab@groupstudy.com
> Subject: RE: Help with Local Preference
>
>
> You guys _really_ need to turn off sync. You are perpetuating all sorts
> of
> nasty uses for otherwise useful BGP tools like confederations ;-) Not to
> mention making me doubt what I thought I knew.
>
>
> At 09:00 PM 10/14/2002 -0400, Paglia, John (USPC.PCT.Hopewell) wrote:
> >Probably because eBGP routes are accepted by the directly connected eBGP
> >peer regardless of synchronization-they just wont propogate to that
> routers
> >iBGP peers.
> >
> >It accepted the eBGP over the iBGP routes because iBGP routes have to be
> >synchronized, and in your case they weren't. You can get around this with
> >confederations as well.
> >
> >John
> >
> > > -----Original Message-----
> > > From: D. Lee [SMTP:dongweylee1@attbi.com]
> > > Sent: Monday, October 14, 2002 8:42 PM
> > > To: Mahmud, Yasser
> > > Cc: ccielab@groupstudy.com
> > > Subject: Re: Help with Local Preference
> > >
> > > Thank you, and you are right. Why is that??
> > >
> > > I knew the internal route from IBGP peer is not synchronized when I
> > > checked
> > > it with sho ip bgp x.x.x.x.
> > >
> > > ----- Original Message -----
> > > From: "Mahmud, Yasser" <YMahmud@Solutions.UK.ATT.com>
> > > To: "'D. Lee'" <dongweylee1@attbi.com>
> > > Cc: <ccielab@groupstudy.com>
> > > Sent: Monday, October 14, 2002 3:50 PM
> > > Subject: RE: Help with Local Preference
> > >
> > >
> > > > It seems as a synchronization problem, use the <no sync> command on
> R2
> > > >
> > > > Yasser Mahmud
> > > >
> > > > -----Original Message-----
> > > > From: D. Lee [mailto:dongweylee1@attbi.com]
> > > > Sent: Monday, October 14, 2002 10:08 PM
> > > > To: Cristian Henry H; Paglia, John (USPC.PCT.Hopewell)
> > > > Cc: 'Peter van Oene'; ccielab@groupstudy.com
> > > > Subject: Re: Help with Local Preference
> > > >
> > > >
> > > > I do not know what I am missing, but it seems like it always prefers
> the
> > > > external route in my lab.
> > > > (Even though the internal route with a higher local preference)
> > > >
> > > > ----- Original Message -----
> > > > From: "Cristian Henry H" <chenry@reuna.cl>
> > > > To: "Paglia, John (USPC.PCT.Hopewell)" <JPaglia@NA2.US.ML.com>
> > > > Cc: "'Peter van Oene'" <pvo@usermail.com>; <ccielab@groupstudy.com>
> > > > Sent: Monday, October 14, 2002 2:33 PM
> > > > Subject: Re: Help with Local Preference
> > > >
> > > >
> > > > > Also it is propaged troughout an Confederation!
> > > > >
> > > > > "Paglia, John (USPC.PCT.Hopewell)" wrote:
> > > > > >
> > > > > > Local pref propogates throughout an AS, so with all things equal
> it
> > > > should
> > > > > > go thru r2.
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Peter van Oene [SMTP:pvo@usermail.com]
> > > > > > > Sent: Monday, October 14, 2002 3:55 PM
> > > > > > > To: Cristian Henry H
> > > > > > > Cc: ccielab@groupstudy.com
> > > > > > > Subject: Re: Help with Local Preference
> > > > > > >
> > > > > > > Pref should override this.
> > > > > > >
> > > > > > > At 04:14 PM 10/14/2002 -0300, Cristian Henry H wrote:
> > > > > > > >Externals first, then internals
> > > > > > > >
> > > > > > > >"D. Lee" wrote:
> > > > > > > > >
> > > > > > > > > R1 and R2 are IBGP peers within the same AS, and they are
> both
> > > > EBGP
> > > > > > > peering
> > > > > > > > > with other AS.
> > > > > > > > >
> > > > > > > > > A route-map for local preference was created on R2 for a
> > > > destination
> > > > > > > X.
> > > > > > > > >
> > > > > > > > > R1 learned a route to X via his EBGP peer, and it was
> assigned
> > > a
> > > > local
> > > > > > > > > preference 100.
> > > > > > > > > R2 also learned a route to X via his EBGP peer, and it was
> > > > assigned a
> > > > > > > > higher
> > > > > > > > > local-pref 200
> > > > > > > > > because of using the route-map. R2 passed the route with
> > > higher
> > > > > > > > local-pref to
> > > > > > > > > R1.
> > > > > > > > >
> > > > > > > > > >From the point of view of R1, the best path to X is
> through
> > > his
> > > > EBGP
> > > > > > > > peer or
> > > > > > > > > R2??
> > > > > > > > >
> > > > > > > > > The router will prefer its external route or its internal
> > > route
> > > > with
> > > > > > > higher
> > > > > > > > > local preference??
> > > > > > > > >
> > > > > > > > > Thanks for all the feedback ...
> > > > > > > >
> > > > > > > >--
> > > > > > > >Cristian E. Henry
> > > > > > > >REUNA
> > > > > > > >
> > > > > > > >E-mail: chenry@reuna.cl
> > > > > > > >Fono: 56-2-3370336
> > > > >
> > > > > --
> > > > > Cristian E. Henry
> > > > > REUNA
> > > > >
> > > > > E-mail: chenry@reuna.cl
> > > > > Fono: 56-2-3370336
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