Thanks Tony! Great explanation.
-----Original Message----- From: Tony Singh [mailto:[email protected]] Sent: Wednesday, January 29, 2014 8:26 PM To: Christopher Lemish Cc: [email protected] Subject: Re: [OSL | CCIE_RS] MSDP: Confederation vs. eBGP Question Correct, that's a real confusing topology by the way, nice Ok so your BSR is to disseminate the RP information dynamically so that PIM routers know where he is to build the SPT and RPT trees.....BSR encoded information is encapsulated and sent within the PIM hellos every 30 seconds to multicast address 224.0.0.13 TTL 1 and protocol number 103 An RPF check is performed on these messages as there multicast packets effectively and would need to pass this check before there flooded out on a hop by hop basis PIM-SMv2 domains only not v1, just adding an image of a packet capture and what it looks like on wire http://aitaseller.files.wordpress.com/2012/09/bsr-router-rp-adv.jpg but key is always ask yourself how many RP's are in the topology and go from there. -- BR Tony Sent from my iPad > On 30 Jan 2014, at 00:56, Christopher Lemish <[email protected]> > wrote: > > Thanks for the quick response! > > Oh, ok. Well, we are doing redistribution of EIGRP from process 78 to > process 457. BGP AS 65245 (R2|R54|R5) has an eBGP neighbor relationship to > BGP AS 65078 (R7|R8). All routers (R2-R8) are in a Confederation. > > R5 was an RP in the AS 65245. My interpretation was looking at R5-R7 as eBGP > even though there is a confederation. I made R7 the Bootstrap router in that > AS 65078 and created an MSDP peering relationship b/t the two. Looking at > the solution, it did not call for an MSDP peer. > > Just trying to figure out what the rule is for MSDP. I think you answered > it. If I am hearing you correctly, if routers are reachable via an IGP, an > MSDP peering relationship is not required. If there is a true eBGP > relationship and true separate AS's, an RP is required in each AS and the two > RP's will communicate the joining of multicast groups to their hosts in > disparate Multicast domains? > > Thank you, > Chris > > Christopher Lemish, CCNP/MCSE > Network Consulting Engineer | CDW > Phone: 732.982.0074 | Mobile: 646.276.3466 > > > > > -----Original Message----- > From: Tony Singh [mailto:[email protected]] > Sent: Wednesday, January 29, 2014 7:41 PM > To: Christopher Lemish > Cc: [email protected] > Subject: Re: [OSL | CCIE_RS] MSDP: Confederation vs. eBGP Question > > > I can't recall the lab but how many RP's did you have? If there was only one > then no need as it's the same IGP domain, MSDP is for inter-domain multicast > and RP's to share (S,G) sa-cache messages be it eBGP or two different IGP > domains. > > -- > BR > > Tony > >> On 30 Jan 2014, at 00:27, Christopher Lemish <[email protected]> >> wrote: >> >> Guys, >> >> I ran across this in Vol3 Lab 8 T-shoot. I did the task and brought up an >> MSDP peer b/t R5 & R7. The AS is a confederation but there is an eBGP >> peering relationship b/t R5-R7. The task required BSR to be configured, >> sparse mode on appropriate interfaces and the distance command in EIGRP to >> change the external redistributed routes to 90. >> >> Based on the DSG, I assume that MSDP peering is not required for eBGP peers >> within an AS, but is required b/t regular eBGP peers? >> >> Turning up this MSDP peer did not hurt anything. Would we lose points in >> the lab if this was configured? Would this even be considered in the script >> that checks our work when the lab is finished? >> >> Thank you, >> Chris >> >> >> _______________________________________________ >> Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: >> >> iPexpert on YouTube: www.youtube.com/ipexpertinc _______________________________________________ Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: iPexpert on YouTube: www.youtube.com/ipexpertinc
