From: cebuano (cebu2ccie@cox.net)
Date: Thu Jan 16 2003 - 03:58:11 GMT-3
After reading the Practical Design pages, I missed this very important
paragraph...
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm#xtocid2
043950
Turning off synchronization on Router A will cause Router A to advertise
network 203.250.15.0. This step is required because Router A will not
synchronize with OSPF because of mask differences. For the same reason,
synchronization should also be turned off on Router B so that it can
advertise network 203.250.13.0.
So, does anyone have a link that I can look up as to why the different
Masks will cause problems with Synchronization?
TIA.
Elmer
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Joe Chang
Sent: Wednesday, January 15, 2003 5:53 PM
To: ccielab@groupstudy.com
Subject: Re: BGP Synchronization Rule - changed in 12.0??
Cebuano wrote:
>My question is this.if synchronization is turned ON (default).even if
>the BGP routes are learned via OSPF.BGP does not install them in its
>routing table. Is this how synchronization affects iBGP peer
>advertisements?
I think in this case the rule of synchronization still holds because the
BGP
routes A is advertising have been successfully installed in the BGP
table of
B. The routing table (which is a separate entity from the BGP table, of
course) does not install the BGP routes because of the lower AD of OSPF
(which you have already discovered in your second example). In other
words,
what you observed is not a failure of synchronization because a
successful
update of the BGP table does not necessarily mean the routing table must
also reflect that update. In your first example router B should be able
to
advertise its IBGP routes to the external AS.
.
.
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