From: Jian Gu (guxiaojian@gmail.com)
Date: Mon Apr 10 2006 - 02:52:44 GMT-3
Scott, please see in line.
On 4/8/06, Scott Morris <swm@emanon.com> wrote:
>
> I'd be interested in what all the other configs and traffic looks
> like. The
> routers have very different packets that are exchanged for a (*,G) join
> versus a (S,G) join. The first is actually directed to the RP, the second
> is actually directed towards the source.
>
> So in your testing environment, is it possible that the RP is actually the
> source (perceived source?) of your multicast traffic that you are testing?
Source is directly connected to RP.
That may account for what you are seeing here, but in a live environment,
> with real multicast servers you shouldn't see this. Only the initial
> requestor (with the IGMP setup) has the capability of changing itself from
> shared to source tree. Everyone else would be a transit, unless they were
> involved with other conversations and responding as well (e.g. you used
> the
> "ip igmp join-group" in many locations).
>
> But in more standard deployments, I don't believe you should see that.
I agree, I can not recreate the problem now, stil I have no idea why those
entries are created. Is there any other machanism in multicast which will
triggle creation of (S,G) in transit routers besides explicit (S,G) joins
all the way down from last hop router?
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE
> #153, CISSP, et al.
> CCSI/JNCI
> IPExpert CCIE Program Manager
> IPExpert Sr. Technical Instructor
> swm@emanon.com/smorris@ipexpert.com
> http://www.ipexpert.com
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Jian
> Gu
> Sent: Saturday, April 08, 2006 11:32 PM
> To: Bob Sinclair
> Cc: Cisco certification
> Subject: Re: (S,G) entries in shared tree router
>
> I saw (S,G) entries in share tree routers where pim spt-threshold is set
> to
> infinity for the group G throughout the multicast routers between sender
> and
> receiver, and I want to understand the reason behind it.
>
> On 4/8/06, Bob Sinclair <bob@bobsinclair.net> wrote:
> >
> > Jian,
> >
> >
> > I would expect only (*,G) state downstream from the RP to the last-hop
> > router. I would expect to find both (*,G) and (S,G) state between the
> > RP and the first-hop router. What are you seeing? Does your shared
> > tree overlap the SPT from the RP to the source?
> >
> > HTH,
> >
> > Bob Sinclair
> > CCIE #10427, CCSI 30427
> > www.netmasterclass.net
> >
> > ----- Original Message -----
> > *From:* Jian Gu <guxiaojian@gmail.com>
> > *To:* Cisco certification <ccielab@groupstudy.com>
> > *Sent:* Saturday, April 08, 2006 1:35 PM
> > *Subject:* (S,G) entries in shared tree router
> >
> > Hi, all,
> >
> > pim spt-threshold is set to infinity, in what scenario, there will be
> > (S,G)
> > states on routers in shared tree routers (downstream RP)?
> >
> > Jian
> >
> > ______________________________________________________________________
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