From: Masood Malik (malikm24@xxxxxxxxxxx)
Date: Tue Apr 24 2001 - 20:04:29 GMT-3
RE: BGP filtering without IP address FiltersHi,
The main difference between no-export and no-advertise is as follows.
When no-export community is set in an AS for a route it will be passed through
all the routers in the same AS (IBGP) and also to the next neighbour AS
(EBGP). However, this neighbour AS will not pass it to its up stream AS.
Thus no-exports cannot work in the same AS.
When you set no-advertise community on a router in any AS, the route will not
be advertised to any neighbour AS whether it is same (IBGP) or different
(EBGP).
e.g. if you have following scenario
R1 (AS100)---R2 (AS100)----R3(AS200)------R4(AS300)
If no-export community is set on a route entering R1. You will see the route
in R2 and R3 but not in R4.
If no-advertise community is set on a route entering R1. The route will be
missing in R2, R3 or R4.
Note: In order for all this to work correctly, ensure setting send-community
to the neighour AS peers in each router.
regards
Masood
----- Original Message -----
From: Chia Kim Seng, Consultant, SCSNW-Sales
To: 'Masood Malik' ; Vladimir Shchutski ; Dean, Justin ;
ccielab@groupstudy.com
Sent: Tuesday, April 24, 2001 11:46 AM
Subject: RE: BGP filtering without IP address Filters
Can I use no-export community instead?
Regards
Chia Kim Seng
SCS Networks Pte Ltd
7 Bedok South Road
Singapore 469272
Tel : 065-2403164
Fax: 065-2403110
-----Original Message-----
From: Masood Malik [mailto:malikm24@hotmail.com]
Sent: Tuesday, April 24, 2001 6:21 AM
To: Vladimir Shchutski; Dean, Justin; ccielab@groupstudy.com
Subject: Re: BGP filtering without IP address Filters
set no-advertise community for 1.1.1.1 on R2
regards
Masood
----- Original Message -----
From: "Vladimir Shchutski" <vshchutski@yahoo.com>
To: "Dean, Justin" <Justin.Dean@nrtinc.com>; <ccielab@groupstudy.com>
Sent: Tuesday, April 24, 2001 7:42 AM
Subject: Re: BGP filtering without IP address Filters
> try community names.
>
> Regards,
> Vladimir.
>
> --- "Dean, Justin" <Justin.Dean@nrtinc.com> wrote:
> > I am trying to have R2 filter the 1.1.1.1 from being
> > advertised to R3. The
> > requirement is that you cannot filter by ip address.
> > I thought I could tag
> > it with a route-map at R1 then match tag at R2 and
> > dump it, but I get an
> > error trying to put the set tag in the route-map and
> > apply it to the
> > neighbor outbound. I also tried to prepend as's, but
> > since R1 and R2 are in
> > same as the route shows as "i". Any Ideas? justin
> >
> >
> > 1.1.1.1-------R1----IBGP---R2---EBGP---R3----
> > **Please
> > read:http://www.groupstudy.com/list/posting.html
> >
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