Re: OSPF DR/BDR

just to add...

WRT dbd packet which is used to compare what LSA's the neighbour does and doesn't have already therefore this in itself by design is a flooding preventative measure i.e router A has x route and router B has x y routes in the dbd summary they exchange, so therefore router A will send a LSR packet to router B for prefix y in which router B will reply with a LSU packet

--
BR
Tony
Sent from my iPad
On 25 Mar 2013, at 05:25, Joe Astorino <joeastorino1982_at_gmail.com> wrote:
> Another thing to consider is that once you get to exchange state with
> a neighbor you are actually exchanging DBD and after that LSA
> information.
> 
> With 99 neighbors you have to go through all the states from down to
> full for each of them and you have all that overhead to go with it.
> 
> In DROTHER you only get to two-way which basically just means both
> sides have heard hellos and acknowledge the other neighbor but you
> don't have the real CPU intensive stuff happening
> 
> Sent from my iPad
> 
> On Mar 21, 2013, at 4:06 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
>> 
>> 
>> Blogs and organic groups at http://www.ccie.net
>> 
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
> 
> 
> Blogs and organic groups at http://www.ccie.net
> 
> _______________________________________________________________________
> Subscription information may be found at: 
> http://www.groupstudy.com/list/CCIELab.html
Blogs and organic groups at http://www.ccie.net