RE: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17)

Russ White <ruwhite@cisco.com> Tue, 15 January 2002 23:45 UTC

Date: Tue, 15 Jan 2002 18:45:00 -0500
From: Russ White <ruwhite@cisco.com>
Reply-To: Russ White <riw@cisco.com>
To: Anoop Ghanwani <anoop@lanterncom.com>
Cc: Babu Prabesh <bprabesh@cosinecom.com>, idr@merit.edu
Subject: RE: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17)
In-Reply-To: <58BE468BAC66D511AFE6000347251A2DED44C9@morpheus.lanterncom.com>
Message-ID: <Pine.GSO.4.21.0201151844530.21052-100000@ruwhite-u10.cisco.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"
Sender: owner-idr@merit.edu
Precedence: bulk

Agreed....

:-)

Russ

On Tue, 15 Jan 2002, Anoop Ghanwani wrote:

> 
> I think what the text is trying to say is that 
> it is not possible to deaggregate a route once it
> has been aggregated.  If so, it would make sense
> to modify the text in 9.1.4 to say just that.
> 
> If that's not what the text is saying, then please
> correct me.
> 
> -Anoop
> 
> > -----Original Message-----
> > From: Russ White [mailto:ruwhite@cisco.com]
> > Sent: Tuesday, January 15, 2002 5:02 AM
> > To: Babu Prabesh
> > Cc: idr@merit.edu
> > Subject: Re: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17)
> > 
> > 
> > 
> > Nope--those woul dbe two seperate routes, with their own as
> > paths, so it won't matter if you send both of them. Presumably,
> > rtrb knows about the /16 locally, which is why it has the static,
> > so no looping should occur. 
> > 
> > I'm not certain how you would de-aggregate in this way....
> > 
> > :-)
> > 
> > Russ
> > 
> > On Mon, 14 Jan 2002, Babu Prabesh wrote:
> > 
> > > Section 9.1.4: overlapping routes states:
> > > 
> > > "If a BGP speaker chooses to aggregate, then it MUST add
> > > ATOMIC_AGGREGATE attribute
> > > to the route. A route that carries ATOMIC_AGGREGATE 
> > attribute can not be
> > > de-aggregated.
> > > That is, the NLRI of this route can not be made more specific.
> > > Forwarding along such a
> > > route does not guarantee that IP packets will actually 
> > traverse only ASs
> > > listed in the
> > > AS_PATH attribute of the route".
> > > 
> > > I was unsure of what de-aggregation means.
> > > Consider an example
> > > 
> > >                bgp                  bgp
> > >   RTRA---------RTRB----------RTRC
> > > 
> > >  RTRA sends 5/8 with ATOMIC_AGGREGATE set to RTRB.
> > >  RTRB has a 5/16 route (via static).
> > > 
> > > Is the draft indicating that RTRB should only
> > > advertise 5/8 to RTRC and not advertise 5/16.
> > > 
> > > Thanks
> > >  Babu
> > > 
> > > 
> > ##############################################################
> > ##############
> > > ########################## This email communication may 
> > contain CONFIDENTIAL
> > > INFORMATION and is intended only for the use of the 
> > intended recipients
> > > identified above.  If you are not the intended recipient of this
> > > communication, you must not use, disclose, distribute, copy 
> > or print this
> > > email. If you have received this communication in error, 
> > please immediately
> > > notify the sender by reply email, delete the communication 
> > and destroy all
> > > copies.
> > > 
> > ##############################################################
> > ##############
> > > ##########################
> > > 
> > 
> > _____________________________
> > riw@cisco.com <>< Grace Alone
> > 
> 

_____________________________
riw@cisco.com <>< Grace Alone

Re: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17) Yakov Rekhter
RE: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17) Russ White
Re: ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17) Russ White
ATOMIC AGGREGATE (section 9.1.4 of bgp 4-17) Babu Prabesh