Re: msdp sa message

Team!!!

Thanks Dan. Yep, the doc also mentioned that ... looks pretty handy indeed
...

Brian - that link is awesome!!! Early in the document it helps me learn and
filled some holes in my understanding! In fact the first few bullet list
items are very helpful to me.

I also want to thank Tyson who labbed this as well!!!

Thanks team,

You all rock! I hope you all have a great weekend!

Andrew

On Fri, Jan 28, 2011 at 2:01 PM, Dan Shechter <danshtr_at_gmail.com> wrote:

> A tip: use "*ip msdp mesh-group"* command to overcome MSDP RPF problems in
> the lab.
>
> So nice of Jeff Doyle to mention that... :)
>
>
> HTH,
> Dan #13685 (RS/Sec/SP)
> The CCIE troubleshooting blog: http://dans-net.com
>
>
> On Fri, Jan 28, 2011 at 8:55 PM, Brian McGahan <bmcgahan_at_ine.com> wrote:
>
> > Whether the SA is accepted or not uses a more complicated logic than a
> > normal
> > RPF check. It is RFC defined, and you can see more info about it here:
> >
> http://www.cisco.com/en/US/docs/ios/12_3t/12_3t4/feature/guide/gt_msdp.html
> >
> >
> > HTH,
> >
> > Brian McGahan, CCIE #8593 (R&S/SP/Security)
> > bmcgahan_at_INE.com
> > Internetwork Expert, Inc.
> > http://www.INE.com
> > Toll Free: 877-224-8987 x 705
> > Outside US: 775-826-4344 x 705
> >
> > From: ALL From_NJ [mailto:all.from.nj_at_gmail.com]
> > Sent: Thursday, January 27, 2011 9:33 PM
> > To: abderrahim sadki
> > Cc: Brian McGahan; abderrahim sadki; ccielab_at_groupstudy.com; Narbik
> > Kocharians
> > Subject: Re: msdp sa message
> >
> > Hello and good evening wonderful team,
> >
> > A quick question for clarification on the RPF check that each MSDP peer
> > would
> > do in a larger network w/ multiple autonomous systems (or a CCIE
> scenario)
> > ...
> >
> > Lets say you have two separate AS, and YOU ARE NOT sharing all routes
> > between.
> > There is no default or summary routes between the two AS.
> >
> > MSDP peers share info and each learns about another source in the other
> AS.
> > Here is my confusion:
> >
> > 1) In this scenario, won't you have a RPF failure or will each MSDP peer
> > simply drop the advertisement since they do not know anything about the
> > others
> > source?
> >
> > 2) If using BGP to overcome any RPF failures or to solve this scenario,
> do
> > you
> > only have to advertise the source address from the other AS?
> >
> > I believe you have to advertise each sending source address ...
> >
> > 3) Does each RP/MSDP peer become the next hop then in the BGP table?
> >
> > Sorry team ... my lab is not up and running yet.
> >
> > I am also interested in hearing others comments, gotchas, and good
> advice.
> > Many TIA team and have a good night,
> >
> > Andrew
> >
> >
> >
> >
> > On Thu, Jan 27, 2011 at 3:36 PM, abderrahim sadki
> > <sadkia_at_gmail.com<mailto:sadkia_at_gmail.com>> wrote:
> > Thank you Narbik and Brian. It is clear.
> >
> > Abderrahim
> >
> >
> > On 01/26/2011 01:23 AM, Brian McGahan wrote:
> > The only action taken is that the (S,G) entry is installed in the SA
> cache.
> > MSDP is just used to tell the RPs where the sources are, it doesn't have
> > anything to do with building the tree. PIM is still used for the
> formation
> > of
> > the tree, which occurs once the RP receives a (*,G) PIM join for a group
> > that
> > is in the SA cache. The (S,G) entry will then be installed in the
> > multicast
> > routing table, and the (S,G) tree joined back to the source.
> >
> >
> > HTH,
> >
> > Brian McGahan, CCIE #8593 (R&S/SP/Security)
> > bmcgahan_at_INE.com
> >
> >
> > -----Original Message-----
> > From: nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>
> > [mailto:nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>] On Behalf
> Of
> > abderrahim sadki
> > Sent: Tuesday, January 25, 2011 2:24 PM
> > To: ccielab_at_groupstudy.com<mailto:ccielab_at_groupstudy.com>
> > Cc: sadkia_at_gmail.com<mailto:sadkia_at_gmail.com>
> > Subject: msdp sa message
> >
> > Hi all,
> >
> > After going through the multicast configuration guide I am a bit
> confused:
> >
> > When the MSDP peer receives the SA message from the other domain, does he
> > send
> > a (S,G) join message back to the RP? or does it decapsulate it and
> forwards
> > it
> > to the receivers.
> >
> > Thanks,
> > Abderrahim
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
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> >
> >
> >
> >
> >
> >
> >
> >
> > --
> > Andrew Lee Lissitz
> > all.from.nj_at_gmail.com<mailto:all.from.nj_at_gmail.com>
> >
> >
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> >
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-- 
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net