Re: OSPF DBDs

That's right. I forgot about the "INIT" bit.

I'm not sure but....
This may be an implementation issue. I see it as being a deterministic
behavior thing since this still happens on a point-to-point link as well.
Just no election of the DR.

Where is Peter Lapukhov. He usually pretty good at explaining some of these
details.

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 18:25:47 +0000
> To: Paul Negron <negron.paul_at_gmail.com>, <ccielab_at_groupstudy.com>
> Subject: 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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