From: Godswill Oletu (oletu@inbox.lv)
Date: Thu Jun 01 2006 - 13:57:01 ART
Hi,
This topic was beaten to death the past few weeks on the group and the general
concession is that, when there is a tie on the priority vlaues, the highest
Router-ID wins, Cisco online documentation have various pages confirming this
as well. But, I do not know if anyone labbed this up and fool-proof this
concept.
I am have labbed that exact scenario, that required that a particular router
be elected the DR in segment of two routers, the neighbor or priority commands
are not to be used.
The results I am getting is not consistent across the board:
Little preview of my configures:
Rack1R2:
interface Serial0
no ip address
encapsulation frame-relay
no frame-relay inverse-arp
!
interface Serial0.204 point-to-point
ip address 144.1.24.2 255.255.255.0
ip ospf network broadcast
frame-relay interface-dlci 204
!
router ospf 1
router-id 222.2.2.2
log-adjacency-changes
network 144.1.24.2 0.0.0.0 area 0.0.0.0
network 150.1.2.2 0.0.0.0 area 0.0.0.0
!
-----------------------------------------------------------------------------
-- Rack1R4: interface Serial0/0 no ip address encapsulation frame-relay no frame-relay inverse-arp ! interface Serial0/0.402 point-to-point ip address 144.1.24.4 255.255.255.0 ip ospf network broadcast frame-relay interface-dlci 402 ! router ospf 1 router-id 150.1.4.4 log-adjacency-changes network 144.1.24.4 0.0.0.0 area 0.0.0.0 network 150.1.4.4 0.0.0.0 area 0.0.0.0 ! ----------------------------------------------------------------------------- ------- Results: Rack1R2#clear ip ospf process Rack1R2#sho ip ospf nei Neighbor ID Pri State Dead Time Address Interface 150.1.4.4 1 FULL/DR 00:00:37 144.1.24.4 Serial0.204 Rack1R2#Rack1R4#show ip ospf nei Neighbor ID Pri State Dead Time Address Interface 222.2.2.2 1 FULL/BDR 00:00:32 144.1.24.2 Serial0/0.402 Rack1R4#
Despite the fact that Rack1R4 have the lowest Router-ID, it was elected the DR for that segment and Rack1R2 who have the highest Router-ID settled for the less fancy job of a BDR.
Now............
Rack1R4#clear ip osp nei Rack1R4#sho ip ospf nei Neighbor ID Pri State Dead Time Address Interface 222.2.2.2 1 FULL/DR 00:00:39 144.1.24.2 Serial0/0.402 Rack1R4#
Rack1R2#sh ip ospf nei Neighbor ID Pri State Dead Time Address Interface 150.1.4.4 1 FULL/BDR 00:00:34 144.1.24.4 Serial0.204 Rack1R2#
Now, the roles have been revised, completely negativing the 'supposed' influence that a higher Router-ID should have in the DR/BDR election process.
Or, are mine missing something here? Maybe my coffee have not sink in yet...but your contribution is highly welcome.
Thanks. Godswill Oletu
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:31 ART