Re: OSPF DBDs

I think that's right Paul. Was looking at a capture and trying to make sense of it all. The INIT, MORE, and MASTER bit are set in the first two DBDs (one by each router). Subsequently, only the DR sets the MASTER bit.
Why is the election done at this time, when information needed to decide DR/BDR is contained in Hello packets?

 
Sent from my BlackBerry wireless device from MTN

-----Original Message-----
From: Paul Negron <negron.paul_at_gmail.com>
Date: Mon, 16 May 2011 12:14:44
To: <jnhdny_at_gmail.com>; <ccielab_at_groupstudy.com>
Subject: Re: OSPF DBDs

DBD's are also used to enforce the "Mastership" of an OSPF peering
relationship. During the "Exstart" phase of the peering, OSPF sends DBD's to
enforce a Master and Slave state for peers that will Start the Exchange.

The "Master" bit and the "More Bit" are sent initially by both peers in a
DBD but will negotiate based on the higher router-id. The peer with the
higher router-id has its "More" bit and "Master" bit remain set. The lower
router-id does not set the "Master" bit on the next DBD just prior to
exchanging LSA's.

If this is seen as not being correct by another CCIE or CCIE Candadite.
Please let me know. I am always looking for different explanations or views
or correction if NEEDED.

Paul

-- 
Paul Negron
CCIE# 14856 CCSI# 22752
Senior Technical Instructor
www.micronicstraining.com
> From: <jnhdny_at_gmail.com>
> Reply-To: <jnhdny_at_gmail.com>
> Date: Mon, 16 May 2011 17:45:33 +0000
> To: <ccielab_at_groupstudy.com>
> Subject: OSPF DBDs
> 
> Please, does anyone know *why* DBDs have to be exchanged before actual LS
> requests and updates are sent? Why not just send all the LSAs in the database
> to the neighbour?
> Sent from my BlackBerry wireless device from MTN
> 
> 
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