From: Raśl
Date: Fri Mar 10 2006 - 22:24:15 GMT-3
?
Remember that the elecion is not preemptive, the only way you can assure that
one router will become the DR is that the other ones have the "ip ospf
priority 0" under the interface. There is no other way to "be sure".
If you have one router with Priority 10, one with Priority 20, and other with
Priority 30, the DR will be the one that start the OSPF process first, not
necesarily the one with the highest priority. If you put an interface with
priority 0, that one will never become the DR.
________________________________
From: nobody@groupstudy.com on behalf of Nadeem Lughmani
Sent: Fri 3/10/2006 7:06 PM
To: ccielab@groupstudy.com
Subject: Understanding "Neighbor x.x.x.x Priority" under NBMA OSPF
Greetings,
I am practicing DR/BDR election on NBMA networks. My topology is described
below. I am trying to influence DR/BDR election based on "neighbor x.x.x.x
priority" command. (while keeping the default priority under interface). I
don't think its working.
I gave priority 20 to neighbor 150.50.100.5 but I don't see this router
becoming DR.
Any help in understanding "neighbor x.x.x.x priority" command is
appreciated.
R1------FR-Switch -----------R2
R1#
interface Serial1/1/0.256 multipoint
ip address 150.50.100.12 255.255.255.224
no arp frame-relay
frame-relay map ip 150.50.100.5 105 broadcast
no frame-relay inverse-arp
end
R1#router ospf 1
router-id 200.0.0.12
network 150.50.100.12 0.0.0.0 area 0
neighbor 150.50.100.5 priority 20
R2#
interface Serial1/1/0
ip address 150.50.100.5 255.255.255.224
encapsulation frame-relay
no arp frame-relay
frame-relay map ip 150.50.100.12 501 broadcast
no frame-relay inverse-arp
end
R2#router ospf 1
network 150.50.100.5 0.0.0.0 area 0
neighbor 150.50.100.12 priority 10
R1#sh ip ospf ne
Neighbor ID Pri State Dead Time Address Interface
200.0.0.5 1 FULL/BDR 00:01:56 150.50.100.5
Serial1/1/0.256
|---------> Shouldn't this be DR?
R2#sh ip ospf ne
Neighbor ID Pri State Dead Time Address Interface
200.0.0.12 1 FULL/DR 00:01:45 150.50.100.12
Serial1/1/0
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