At 12:16 PM -0500 1/7/02, Andy Leaning wrote: >I'm currently studying for this exam too so I could well be wrong, >forgive me if I am... > >My understanding is that the dr and bdr are there to reduce >LSA traffic when there are numerous routers on a shared network >- instead of everyone talking to everyone it's everyone to a dr. > >On a point to point link there are only two routers so the excessive traffic >problem won't occur and the DR/BDR aren't required. As such it's just a >case of configuring each router to know about the other (using >the neighbor statement), after this they send the usual hello's to each >other to build and maintain the link state database. > >If this is wrong can someone correct me. > >Andy Leaning
As for point-to-point, it's even simpler. There is no need for a designated router when there are only two, nor is there a need to configure neighbors -- the neighbor is just the other end of the link. You are correct that the DR and BDR are there to reduce traffic on multiaccess media. On broadcast media such as LANs, their election and topology is usually automatic. Things get more complex in partial mesh networks, where, for example, the hub router MUST become DR even if it doesn't come up first. Also, in no-single-point of-failure partial meshes, where there are two hubs, one hub must be DR, the other hub BDR, and there must be layer 2 connectivity between the DR and BDR. > >""jc fulknier"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> I'm starting the routing track for the CCNP and the cisco press book >> confuses me on nbma. It says that the point to point multicast and point >to >> point unicast are both partial or star meshed and do not need a dr or bdr. >I >> was wondering how everyone stays current if it is not full meshed and has >no >> dr. If anyone could explain this a little more I would really appreciate >it. >> >> JC Fulknier >> CCNA Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=31185&t=31096 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
