From: Anthony Sequeira (Anthony_Sequeira@skillsoft.com)
Date: Tue Nov 20 2007 - 12:21:31 ART
First - make sure you completely understand the synchronization rule of
BGP. This rule states...
"A BGP router should not use or advertise to an external neighbor, a
route that is learned from IBGP unless the route is local or the router
learns it from an IGP."
I always remembered this by thinking about BGP needing to be in
synchronization with the underlying IGP.
BGP synchronization is off by default in IOS release 12.2(8)T and later.
Earlier releases had it turned on by default. I presume that it used to
be on by default because for a long time it was fine to redistribute BGP
routes into the underlying IGP and a full mesh of IBGP was not
considered necessary.
Once you FULLY understand the rule, it should not present any fears for
you in the lab exam.
For example, if they were to have you turn ON synchronization on the
routers, and you are having trouble with prefix advertisement, then you
would know where to look. Perhaps you were supposed to have the prefix
in question advertised in an IGP somewhere!
Anthony J. Sequeira
#15626
Recert Required? No Problem!
http://www.netmasterclass.net/CCIE/Self-Paced-Program/Written
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
shady darwish
Sent: Tuesday, November 20, 2007 9:39 AM
To: Cisco certification
Subject: sychronization ibgp amd igrp
when do we have to use synch and why and when we don't
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:30 ART