From: Godswill Oletu (oletu@inbox.lv)
Date: Thu Jun 01 2006 - 16:14:03 ART
Petr,
Thanks for taking the time to get accross some debug, getting the practical
aspect of these technology, really helps to solidify how knowledge:
On my two router segment, when I shutdown the interface of the other router
and enabled 'debug ip ospf event' on this router, this is what I get:
Rack1R2#
*Mar 1 03:42:51.487: OSPF: Interface Serial0.204 going Down
*Mar 1 03:42:51.491: OSPF: Neighbor change Event on interface Serial0.204
*Mar 1 03:42:51.491: OSPF: DR/BDR election on Serial0.204
*Mar 1 03:42:51.495: OSPF: Elect BDR 150.1.4.4
*Mar 1 03:42:51.495: OSPF: Elect DR 150.1.4.4
*Mar 1 03:42:51.499: OSPF: Elect BDR 150.1.4.4
*Mar 1 03:42:51.499: OSPF: Elect DR 150.1.4.4
*Mar 1 03:42:51.503: DR: 150.1.4.4 (Id) BDR: 150.1.4.4 (Id)
*Mar 1 03:42:51.507: OSPF: Flush network LSA immediately
*Mar 1 03:42:51.507: OSPF: Remember old DR 222.2.2.2 (id)
*Mar 1 03:42:51.511: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on Serial0.204
from FULL to DOWN, Neighbor Down: Interface down or detached
Rack1R2#
*Mar 1 03:42:51.515: OSPF: Neighbor change Event on interface Serial0.204
*Mar 1 03:42:51.519: OSPF: DR/BDR election on Serial0.204
*Mar 1 03:42:51.519: OSPF: Elect BDR 0.0.0.0
*Mar 1 03:42:51.523: OSPF: Elect DR 0.0.0.0
*Mar 1 03:42:51.523: DR: none BDR: none
*Mar 1 03:42:51.527: OSPF: Remember old DR 150.1.4.4 (id)
Rack1R2#
No DR/BDR was elected on my one OSPF enabled router.
The other consistency that I seen is that, shut/no shut seems to give a
consistent result, but the 'clear ip ospf process' does not.
Thanks.
Godswill Oletu
----- Original Message -----
From: Petr Lapukhov
To: Godswill Oletu
Cc: Cisco certification
Sent: Thursday, June 01, 2006 2:34 PM
Subject: Re: DR Election: Incase of a Priority Tie, Highest RID Wins - Truth
or Fallacy?
Godswill,
it's getting late in my timezone, so i'll just throw a little debug
output :))
I enable OSPF on SINGLE router on ethernet segment,
no neighbors alive:
After 40 seconds of wait time
"debug ip ospf events"
shows:
*May 18 13:38:17.394: OSPF: end of Wait on interface FastEthernet0/0.56
*May 18 13:38:17.394: OSPF: DR/BDR election on FastEthernet0/0.56
*May 18 13:38:17.394: OSPF: Elect BDR 151.10.5.5
*May 18 13:38:17.394: OSPF: Elect DR 151.10.5.5
*May 18 13:38:17.394: OSPF: Elect BDR 0.0.0.0
*May 18 13:38:17.394: OSPF: Elect DR 151.10.5.5
*May 18 13:38:17.394: DR: 151.10.5.5 (Id) BDR: none
So you see, DR is elected anyway, even if NO adjacency has been formed :)
After that, if second router will come online, it will quickly learn
available DR
from hello packets.
HTH
Petr
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:31 ART