I understood what you meant, I just can't see the requirement that would cause us to not enable PIM on all interfaces.
On Thu, Aug 25, 2011 at 12:27 PM, Michael Smith <[email protected]> wrote: > Hello Marc, > > I meant to say PIM "was not" supposed to be enabled on the interfaces > leading out of the AS's. The only interface that PIM was to be enabled on is > an interface which was not preferred in BGP. Multicast BGP is used for RPF > checks and also using it will not effect the IPV4 routing. Let me know if > I'm wrong. > > [image: Halo3 Believe] > > > Date: Thu, 25 Aug 2011 11:39:50 -0500 > > Subject: Re: [OSL | CCIE_RS] Multcast BGP - related to lab Vol3 lab 5 > config task 4.4 > > From: [email protected] > > To: [email protected] > > CC: [email protected] > > > > > Thanks for replying. I did some more reading and I now understand MBGP > > is just for RPF checks. I will say this is a topic ripe for blog post > > (hint hint Marko). I didn't see much out there on the topic from any > > of the vendors. > > > > I have moved on to the next lab already but I went back and looked at > > the guide. I don't understand which interface isn't supposed to be PIM > > enabled. I enabled it on all interfaces in the listed ASes, maybe that > > is where I went wrong. > > > > On Thu, Aug 25, 2011 at 11:04 AM, [email protected] > > <[email protected]> wrote: > > > Hello Marc, > > > > > > The purpose of Multicast BGP in this instance was to solve the RPF > failure > > > that was bound to occur because PIM was enabled on all of the > interfaces > > > leading to the other domain. If you notice earlier in the lab BGP was > > > supposed to prefer the path that is not PIM enabled thus resulting in > an RPF > > > failure. You may want to go back and check if you are prefering the > correct > > > paths. I hope this helps. Feel free to let me know I'm wrong :) > > > > > > Sent from my Verizon Wireless Phone > > > > > > ----- Reply message ----- > > > From: "marc abel" <[email protected]> > > > Date: Wed, Aug 24, 2011 5:49 pm > > > Subject: [OSL | CCIE_RS] Multcast BGP - related to lab Vol3 lab 5 > config > > > task 4.4 > > > To: <[email protected]> > > > > > > I am still pretty confused about using multicast BGP and would > > > appreciate any explanation about it including it's purpose and how it > > > works. > > > > > > Specific to this lab and task there is this requirement. > > > > > > Configure inter-domain multicast routing in AS17, AS218, and AS469 > > > such that all multicast routers can ping group joined by R9, as well > > > as group 239.0.0.21 joined by BB1. > > > You are required to configure BGP for this task. > > > > > > > > > So I have setup multcast in those domains, filtering my RP's between > > > the AS's. I have setup MSDP between the 3 RP's. Now I can ping those > > > groups from everywhere. I have not setup multicast BGP yet. So in this > > > scenario what is the purpose of MBGP? Is is just because they said so? > > > Or is it actually supposed to be doing something? > > > > > > Does MBGP actually transport the multicast? or does it just transport > > > the RP information? Or maybe it only makes interfaces pass the RPF > > > check? > > > > > > Really confused. > > > > > > Thank you. > > > _______________________________________________ > > > For more information regarding industry leading CCIE Lab training, > please > > > visit www.ipexpert.com > > > > > > Are you a CCNP or CCIE and looking for a job? Check out > > > www.PlatinumPlacement.com > > > > > > > > > > > > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
