From: Scott Morris (swm@emanon.com)
Date: Sun Aug 08 2004 - 00:07:58 GMT-3
Right... It's about filtering messages destined to one RP or the other (and
you can use the auto-rp part to verify with that cache).
The mapping agent in and of itself will not become the RP. If it happens to
BE an RP, then it is not a MA for itself.
It's not so much that you are worrying that devices "accidently" become the
RP (weird), but more that you make sure you're on the RP's tree.
Look at the command section there. It says that the commmand causes the
router to only accept (*,G) join messages destined for the specific RP
address/groups. That's determining it's action in forwarding join/leave
messages throughout a domain, not so much anything about how IT acts, just
how it acts in forwarding.
The difference also becomes that you can use this command on the RP itself
and acheieve a different kind of filtering.
Now, mind you, I haven't labbed anyhting up striving for the accidental RP
assignment to watch behavior, but I would think that the "ip pim
rp-announce-filter" command would be a better fit for what you appear to be
describing to me.
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, CISSP,
JNCIP, et al.
IPExpert CCIE Program Manager
IPExpert Sr. Technical Instructor
swm@emanon.com/smorris@ipexpert.net
http://www.ipexpert.net
-----Original Message-----
From: ccie2be [mailto:ccie2be@nyc.rr.com]
Sent: Saturday, August 07, 2004 10:53 PM
To: swm@emanon.com; 'john matijevic'; 'Group Study'
Subject: Re: ip pim rp-accept <rp-address> [acl#] command
Hey Scott,
I'm not sure we're on the same page.
I think of this command as added protection against, for example, a static
rp command being mis-configured. Suppose for example, the ip pim rp-address
<ip ad> command had the address of the MA entered by mistake.
Couldn't, under some circumstances, the MA become the rp for some mcast
groups? And, wouldn't the above command prevent that?
Also, from a lab point of view, suppose we were instructed to configure
Auto-rp. And, suppose we were also told to make sure that no routers except
those explicitly meant to be rp's ever accidentally became rp's. In this
case, wouldn't we use the above command on all routers in the mcast domain?
----- Original Message -----
From: "Scott Morris" <swm@emanon.com>
To: "'john matijevic'" <matijevi@bellsouth.net>; "'ccie2be'"
<ccie2be@nyc.rr.com>; "'Group Study'" <ccielab@groupstudy.com>
Sent: Saturday, August 07, 2004 10:31 PM
Subject: RE: ip pim rp-accept <rp-address> [acl#] command
> As an add-on, the candidate-RP or MA portion of the question... If you
are
> a mapping agent, you are just forwarding things anyway, so the rp-accept
> command doesn't reference that IP at all. It will be WHAT is being
learned,
> not who from. (otherwise in BSR-land, that would always be your directly
> connected neighbors)
>
> HTH,
>
>
> Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, CISSP,
> JNCIP, et al.
> IPExpert CCIE Program Manager
> IPExpert Sr. Technical Instructor
> swm@emanon.com/smorris@ipexpert.net
> http://www.ipexpert.net
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
john
> matijevic
> Sent: Saturday, August 07, 2004 8:33 PM
> To: 'ccie2be'; 'Group Study'
> Subject: RE: ip pim rp-accept <rp-address> [acl#] command
>
> Hi Tim,
> The command can best be explained as follows, from the doccd:
> "ip pim accept-rp
> To configure a router to accept join or prune messages destined for a
> specified rendezvous point (RP) and for a specific list of groups, use the
> ip pim accept-rp command in global configuration mode"
> So you are correct that this can be used on any mcast router in a mcast
> domain. But don't take my word for it, test yourself, that's part of the
> fun. :)
>
>
> Sincerely,
>
> John Matijevic, CCIE #13254, MCSE, CNE, CCEA
> Network Consultant
> Hablo Espanol
> 305-321-6232
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> ccie2be
> Sent: Saturday, August 07, 2004 7:29 PM
> To: Group Study
> Subject: ip pim rp-accept <rp-address> [acl#] command
>
> Hi guys,
>
> I just wanted to confirm my understanding of the above command.
>
> My sense is that this command can be used and useful on any mcast router
> in a
> mcast domain. This is true regardless of whether Auto-RP or BSR is
> used. And,
> this is true regardless of whether the router is a c-rp or a MA.
>
> Can anyone confirm this?
>
> TIA, Tim
>
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