Re: OSPF DR and BDR election

It reads placing interface into DR & BDR fields

if the router's priority is greater than 0, it can

1) claim that it is a DR/BDR (if it was elected earlier)

Or

2) not claim and start listening to other routers hellos; then if no one
claims to be DR/BDR, the router will take part in election.

Here's a packet capture showing the fields

http://ipcisco.com/wp-content/uploads/OSPF/A5_OSPF_hello.JPG

--
BR
Tony
> On 21 Feb 2014, at 00:19, vishal bhugra <vishal.bhugra_at_gmail.com> wrote:
>
> Hello Tony
>
> Thanks for your reply,
>
> I am not sure if my question is clear.
>
> If I rephrase my question - Why do a router will put his router ID in BDR
field and not the DR. or why do a router wants himself to be elected as BDR
and not the DR.
>
>
> As mentioned in TCP-IP (Jeff Doyle) Part 1
> <image.png>
>
>
>> On Thu, Feb 20, 2014 at 3:42 PM, Tony Singh <mothafungla_at_gmail.com> wrote:
>>
>> That's all to do with the hello from x being received first who at that
point in time had the highest router-id at the time of the multi-access
election and declared himself as the DR (default priority is 1 for all peers)
>>
>> OSPF DR/BDR elections are not pre-emptive
>>
>> debug ip ospf adjacency will show you what happens when
>>
>> If you had the above scenario then reset the current DR's process (lower
router-id) to enable the highest router-id OSPF router take the DR role
>>
>> --
>> BR
>>
>> Tony
>>
>>
>>
>> > On 20 Feb 2014, at 23:28, vishal bhugra <vishal.bhugra_at_gmail.com> wrote:
>> >
>> > Hello Experts
>> >
>> > While going through the DR and BDR election process. I gone through a
line
>> > wherein during the process of election the router will segregate the
list
>> > of routers who have mentioned themselves as BDR and those who have
>> > mentioned themselves as DR.
>> >
>> > After segregation out of the list of BDR, the elected BDR will be with
the
>> > highest priority and if not then highest Router ID.
>> >
>> > Now my question is .. Why would a router will opt himself for BDR and
not
>> > for DR. Or we can say how a router will come to conclusion that it has
to
>> > go for be a BDR not the DR.
>> >
>> > --
>> > Thanks&regards
>> >
>> > Vishal
>> >
>> > Best way to predict the future ..... is to create it
>> >
>> >
>> > Blogs and organic groups at http://www.ccie.net
>> >
>> > _______________________________________________________________________
>> > Subscription information may be found at:
>> > http://www.groupstudy.com/list/CCIELab.html
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>
>
>
> --
> Thanks&regards
>
> Vishal
> +91 8587900305
>
> Best way to predict the future ..... is to create it
Blogs and organic groups at http://www.ccie.net