From: Marius Venter (marius@aict.co.za)
Date: Wed Mar 15 2006 - 01:48:29 GMT-3
Perhaps it is best to set the priority to 0 when you do not want certain
routers to take over the DR and BDR roles
Marius Venter
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
dszarmach
Sent: Wednesday, March 15, 2006 6:20 AM
To: Bill.McKenzie@bisys.com; Sam K.; ccielab
Subject: RE: Simple OSPF question
to make things worse, the elections are separate, and the BDR always takes
over as DR upon DR failure
so if you have routers A,B,C
assume base config and A wins election based on addressing, with B coming in
2nd
then DR=A and BDR =B
If A fails, B becomes DR automatically
next, election is held for BDR, and C wins becase A is still down
when A rejoins, no elections, and it is stuck with neither job
From there, you might reset OSPF on router B to try to force DR election,
but
again, C becomes the DR automatically (BDR moves up to DR without election)
Next, BDR election happens and Router A wins the title.
Now if you reset OSPF on router C, router A would finally end up as DR
again.
(BDR move up to DR)
This behavior is one of the reasons why you might disable the use of a BDR
on
a hub and spoke NBMA type of network by using priority statements (a wrong
DR
here is worse than no DR!).
-
Doug
________________________________
From: nobody@groupstudy.com on behalf of Bill.McKenzie@bisys.com
Sent: Tue 3/14/2006 8:56 PM
To: Sam K.; ccielab
Subject: Re: Simple OSPF question
Nothing. There is no preemption,
So the first DR doesn't take back over
----- Original Message -----
From: nobody
Sent: 03/14/2006 09:50 PM
To: ccielab@groupstudy.com
Subject: Simple OSPF question
Hi Group,
When the DR goes down then BDR takes over but what happens when the DR comes
back up?
Thanks,
Sam
This archive was generated by hypermail 2.1.4 : Sat Apr 01 2006 - 10:07:38 GMT-3