Re: OSPF DR/BDR

Would you please explain more?

--
Mohammad Mousa
CCIE #36990

On Mar 21, 2013, at 4:05 AM, "shiran guez" <shiranp3_at_gmail.com> wrote:

Think of the difference between having DR/BDR on a LAN/NBMA to not as
the difference of doing a star topology vs doing a full mash which is
more expensive?! (the answer is full mash).

On Thu, Mar 21, 2013 at 8:46 AM, Mohammad Mousa <mohd-mousa_at_hotmail.com> wrote:
> Hello Folks,
>
> Appreciate if someone could clear up this point for me.While I'm reviewing the OSPF, I noticed this issue.
> In the ospf Net-type (broadcast,Non-broadcast). The advantages of using the DR/BDR are:
>
> 1-Minimize the adjacencies.
> 2-Minimize LSA replication.
>
> Suppose we have ethernet LAN segment between four routers R1,R2,R3,R4. R1 is DR, R2 is BDR. I know drothers will stay in the 2-way states. When R3 generate LSU it will go for 224.0.0.6 and then DR will replicate this to all multicast ospf routers 224.0.0.5. My question is suppose we don't have the DR. R3 will generate the LSU to 224.0.0.5 (All routers on that LAN segment). So using DR IS NOT giving me the benefit by reducing the LSA replication on the segment. Am I correct? Any thought will be highly appreciated!
>
> Thanks in advance
> --
> Mohammad
> CCIE #36990
>
>
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-- 
Shiran Guez
MCSE CCNP NCE1 JNCIA-ENT JNCIS-ENT JNCIP-ENT CCIE #20572
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