From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Wed Aug 09 2006 - 02:57:59 ART
This should help answer your question:
BGP Communities Attribute - RFC 1997
no-export
All routes carry this value must not be advertised to outside a BGP
confederation boundary. If neighboring BGP peer is part of BGP
confederation, the peer is considered as inside a BGP confederation
boundary, so the route will be announced to the peer.
no-advertise
All routes carry this value must not be advertised to other BGP
peers.
HTH,
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
spycharlies@hotmail.com
Sent: Tuesday, August 08, 2006 10:07 PM
To: ccielab@groupstudy.com
Subject: BGP Well-know Community
Hey Guys,
I think i might be mixing these 2 communities up. ("no-advertise" &
"no-export")
B4 now, i'd always thought "no-advertise" is used within thesame AS,
while
"no-export" is used btw different AS.
But i was doing some config lately, and i noticed both communities does
thesame funtion.
===================================================================
r1(as100) peers with r2(as200), while r2 peers with r3(as300)
My goal was to advertise network((192.10.100.x/24) on r1. This network
is
passed onto r2 via BGP, but r2 shld'nt pass it on to r3.
r1#
ip as-path access-list 1 permit ^$
!
route-map [N0_EXPORT][NO_ADVERTISE] permit 10
match as-path 1
set community [no-export][no-advertise]
!
route-map [N0_EXPORT][NO_ADVERTISE] permit 1000
!
router bgp 100
..network 192.10.100.0 mask 255.255.255.0
..neighbor 192.10.123.2 remote 200
..neighbor 192.10.123.2 send-community
..neighbor 192.10.123.2 route-map [N0_EXPORT][NO_ADVERTISE] out
My question is, are there situations where u would wanna use
no-export instead of no-advertise or vise-versa??
cheers
Uyota
This archive was generated by hypermail 2.1.4 : Fri Sep 01 2006 - 15:41:56 ART