Dear Markoz, Then things have to deal according to the tasks of CCIE Exam... in this case you are right, one must have to perform the task like that if this is the case.
Regards Sheraz > From: [email protected] > Date: Sat, 26 Jan 2013 10:19:22 -0800 > Subject: Re: [OSL | CCIE_RS] neighbor default-originate > To: [email protected] > CC: [email protected]; [email protected] > > Sheraz, > > I'm pretty sure Lukasz knew why he had an RPF failure. This is to be > expected in the lab and you need to be able to handle it > appropriately. Enabling PIM on all the interfaces may not be an option > (lab restrictions) and knowing how to recover from the RPF failure is > an essential skill for the multicast in the lab. > > Lukasz was trying to replicate this scenario: > http://blog.ipexpert.com/2010/12/29/multicast-rpf-failure-recovery-using-bgp/ > > -- > Marko Milivojevic - CCIE #18427 (SP R&S) > Senior CCIE Instructor / Managing Partner - IPexpert > > On Sat, Jan 26, 2013 at 9:24 AM, Sheraz Sheraz <[email protected]> wrote: > > Please read the below facts it will help you to understand that why RPF is > > being failed after disabling PIM on some interfaces. > > > > > > "When a multicast packet enters a router's interface, it will lookup the > > list of networks that are reachable via that input interface i.e., it > > checks the reverse path of the packet. If the router finds a matching > > routing entry for the source IP of the multicast packet, the RPF check > > passes and the packet is forwarded to all other interfaces that are > > participating in multicast for this multicast group. If the RPF check > > fails the packet will be dropped. As a result the forwarding of the > > packet is decided based upon the reverse path of the packet rather than > > the forward path. RPF routers only forward packets that come into the > > interface that also hold the routing entry for the source of the packet, > > thus breaking any loop" > > > > > > > >> From: [email protected] > >> To: [email protected]; [email protected] > >> Date: Sat, 26 Jan 2013 22:10:10 +0500 > >> Subject: Re: [OSL | CCIE_RS] neighbor default-originate > >> > >> Hi, > >> > >> I think BGP can help to work as base line for multicast traffic but hence > >> you need PIM as well. Although BGP it self needs baseline static or IGP > >> protocols to work properly! You migh have have to enable PIM for multicast > >> traffic to work through out the routing hops and and any IGP! in my case i > >> have enabled PIM with RP on my routers & Multi layer switches as well & > >> have never seen RPF or RP failure! multicast works properly.EGP & IGP > >> protocols are not the suitable choice since "protocol independent > >> Multicast" PIM has been designed for multicast traffic.Look both BGP & IGP > >> protocols takes decision on the base of destination address while > >> multicast needs source base decisions! the nature and working nature of > >> both dynamic protocols & multicast are different. > >> > >> > >> "Multicast RPF, typically denoted simply as RPF, is used in conjunction > >> with a multicast routing protocols such as MSDP and PIM-SM > >> to ensure loop-free forwarding of multicast packets. In multicast > >> routing the decision to forward traffic is based upon source address and > >> not on destination address as is the case with unicast routing. It does > >> this by utilizing either a dedicated multicast routing table or > >> alternatively the router's native unicast routing table" > >> > >> > >> Regards > >> Sheraz > >> > >> > Date: Sat, 26 Jan 2013 00:55:13 +0000 > >> > From: [email protected] > >> > To: [email protected] > >> > Subject: [OSL | CCIE_RS] neighbor default-originate > >> > > >> > Hi All, > >> > > >> > > >> > I am just trying to replicate Marko scenario from blog Multicast RPF > >> > Failure: Recovery Using BGP. I have only changed addressing but other > >> > details are the same. I have ipv4 unicast working and Pim enabled. > >> > I have disabled pim between R3 and R4 on Fa interface and I can see RPF > >> > failure. I set up MP-BGP and that is active as well but..command > >> > neighbor x.x.x.x default-originate does not seem to send default route > >> > to the neighbor. > >> > > >> > > >> > R3 > >> > > >> > router bgp 34 > >> > no bgp default ipv4-unicast > >> > bgp log-neighbor-changes > >> > neighbor 4.4.4.4 remote-as 34 > >> > neighbor 4.4.4.4 update-source Loopback0 > >> > ! > >> > address-family ipv4 multicast > >> > neighbor 4.4.4.4 activate > >> > neighbor 4.4.4.4 default-originate > >> > no auto-summary > >> > > >> > > >> > R3#show bgp ipv4 multicast neighbors 4.4.4.4 | b def > >> > Default information originate, default not sent > >> > > >> > > >> > R4 > >> > > >> > > >> > router bgp 34 > >> > no bgp default ipv4-unicast > >> > bgp log-neighbor-changes > >> > neighbor 3.3.3.3 remote-as 34 > >> > neighbor 3.3.3.3 update-source Loopback0 > >> > ! > >> > address-family ipv4 multicast > >> > neighbor 3.3.3.3 activate > >> > no auto-summary > >> > no synchronization > >> > exit-address-family > >> > R4# > >> > R4#show bgp ipv4 mul > >> > > >> > > >> > R4#show bgp ipv4 mul s > >> > Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down > >> > State/PfxRcd > >> > 3.3.3.3 4 34 61 59 3 0 0 00:34:57 > >> > 0 > >> > > >> > > >> > I guess I misinterpret something. Where is the problem? > >> > > >> > > >> > THanks, > >> > > >> > > >> > _______________________________________________ > >> > 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 > >> > > >> > http://onlinestudylist.com/mailman/listinfo/ccie_rs > >> > >> _______________________________________________ > >> 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 > >> > >> http://onlinestudylist.com/mailman/listinfo/ccie_rs > > > > _______________________________________________ > > 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 > > > > http://onlinestudylist.com/mailman/listinfo/ccie_rs _______________________________________________ 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 http://onlinestudylist.com/mailman/listinfo/ccie_rs
