2 DR IN OSPF AREA 0

[Mangesh Kamerkar]

HI EVERYBODY

I M GETTING 2 DRs IN AREA 0. HOW CAN SOLVE THIS ISSUE.

PLS GUIDE ME

IS THIS HAPPENING BECAUSE I M USING DISCONTIGIOUS NETWORKS ?

[Peter Paluch]

Mangesh,

What you see is absolutely correct and normal. DR routers are elected per each multiaccess network, i.e. on each Ethernet segment you have in an area. Therefore, your area will have as many DRs as how many Ethernet segments are contained within that area.

Are you having any troubles with your network?

Best regards,

Peter

[Mangesh Kamerkar]

Dear peter,

Thanks for your reply, I thaught in a single area there would be only 1 DR.

Now I have solved the issues related with OSPF.

Thanks a lot once again

Thanks & Regards,

Mangesh Kamerkar

M: +91 9987259856

P: +91 2267974077

F: +91 2267993080

[Peter Paluch]

Hello Mangesh,

I thaught in a single area there would be only 1 DR. 

Yes, that is a common misconception. I wonder where that one comes from.

Anyway, I am glad to have helped.

Best regards,

Peter

[wangliok8]

Hi,Mangesh.

According to your drawing. I think there are should be 4 dr in this ospf area. Every "broadcast segment" should have one DR.

[Alfredcfc]

Same doubt,shouldn't  it 4..  So did you figure it out 4 or 2.. kinda confused  please tell 

[Meheretab Mengistu]

Hi Alfredcfc,

When you run OSPF, every Broadcast network will undergo DR/BDR selection at the end of 2WAY state.
According to the diagram, he has 4 Broadcast segments (172.16.10.0, 172.16.50.0, 192.168.10.0, 192.168.54.0) and 2 Point-to-Point connections. There is no need to run OSPF in the segments where he has clients (computers). As a result, he did not run OSPF in the 192.168.x.x segments (I assumed), and he got only 2 DRs.

HTH,
Meheretab

[RyanB]

Deleted - missed the p2p links.

[Alfredcfc]

4 broadcast segments should naturally equate to 4 dr and 4 bdr right?. 172.16.116.0 and172.16.0.0 are the only p2p links i can see of.. So shouldn't there still be 4 dr?.. Sorry i am wrong need some concrete info.

[Meheretab Mengistu]

For each broadcast network OSPF undergoes DR/BDR election, given the fact that it is running. In the above topology, the 192.168.x.x networks are Stub networks -- meaning, OSPF is not configured to find neighbors in those interfaces. As a result, you do not have DR/BDR election on those two networks... The confusion here is that we do not have the actual configuration provided, and we assumed what is configured.

Generally, it does not make sense to run OSPF process in the client-side of the network as you are not expecting to create neighbor relations with end user devices.

HTH,
Meheretab