Re: Unable to ping Multicast group.

Hi Nishant,

To contribute my 2 cents here, this sounds quite similar to a problem I
faced a while back. Here is a link to the archive in case you wish to have a
look.

http://www.groupstudy.com/archives/ccielab/200903/msg01550.html

But just to summarise on what I could suggest is you could try it with a
different IOS version, preferably an older one . I have often had different
behaviours with different IOS versions when it comes to multicast .
And for the question regarding how it is checked in the actual lab, I agree
with Rick. It will have to be verified with an extended ping and also a
source-interface if needed.

Ravi

On Fri, Aug 21, 2009 at 8:08 AM, Nishant Aggarwal <
er.nishantaggarwal_at_gmail.com> wrote:

> I am able to ping from R6 and R3 and I am concerned with R5 only now.
>
> Thanks,
> Nishant Aggarwal
>
> On Fri, Aug 21, 2009 at 12:08 PM, Rick Mur <rmur_at_ipexpert.com> wrote:
>
> > It sounds like R5 is choosing Fa0/0 as standard source interface. Do a
> ping
> > with a source-interface of serial2/0. You should get an ICMP reply then.
> > Especially on frame-relay interfaces it's possible to receive a couple of
> > replies, since frame-relay is not really a broadcasting medium, that's
> why
> > the broadcast traffic is not really well supported. Getting multiple
> replies
> > is nothing wrong with, just normal behavior.
> >
> > It's also normal if the first ping in multicast doesn't get through. You
> > will not have any problems with the 2nd, 3rd and all other packets. I'm
> > convinced that the proctors script will do a repeat 3 or repeat 5 if they
> > ping multicast groups.
> >
> >
> >
> > --
> > Regards,
> >
> > Rick Mur
> > CCIE2 #21946 (R&S / Service Provider)
> > Juniper JNCIA-ER & JNCIA-EX
> > MCSA:Messaging, MCSE
> > Sr. Support Engineer IPexpert, Inc.
> > URL: http://www.IPexpert.com <http://www.ipexpert.com/>
> >
> > On Fri, Aug 21, 2009 at 4:02 AM, Nishant Aggarwal <
> > er.nishantaggarwal_at_gmail.com> wrote:
> >
> >> Hi All,
> >>
> >> Multicast qestion.
> >>
> >> Topology:
> >>
> >> R6 <---FR----> R3 <-----FR-------> R5
> >>
> >> R6 Config:---------------------------------
> >>
> >> Int fa0/0
> >> ip pim sparse-mode
> >> ip igmp join 224.2.2.2
> >> int se2/0
> >> ip pim sparse-mode
> >>
> >> ip pim autorp listener
> >>
> >> R3 Config:---------------------------------
> >>
> >> int lo0
> >> ip pim sparse-mode
> >> int se2/0
> >> ip pim sparse-mode
> >> int se2/1
> >> ip pim sparse-mode
> >>
> >> ip pim autorp listener
> >> ip pim send-rp-announce Loopback0 scope 16 group-list 10
> >> ip pim send-rp-discovery Loopback0 scope 16
> >> access-list 10 per 224.2.2.2
> >>
> >> R5 Config:---------------------------------
> >>
> >> int se2/0
> >> ip pim sparse-mode
> >>
> >> ip pim autorp listener
> >>
> >> There is no other interface on R5 on which multicast is running. I am
> >> getting RP mappings on all devices.
> >>
> >> 1. When I ping 224.2.2.2 (AT R6) from R5, I get not even a single ping,
> >> why?
> >>
> >> 2. When I configure sparse-mode on Fa0/0 of R5, I get 2 or 3 pings, why?
> >>
> >> 3. Also if I go for extended ping (Assume sparse on Fa0/0) by giving
> >> Interface : Serial2/0 and source ip : Fa0/0 ip, I get continuous ping.
> >>
> >> Please guide what is the reason of Qestion 1 and 2.
> >> Also clarify that the script run by proctor to your grade lab, will
> >> check my solution with extended ping and pass it OR just check with
> >> normal ping and fail me??
> >>
> >> What is the solution to resolve the issue?
> >>
> >> Thanks,
> >> Nishant Aggarwal.
> >>
> >>
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Received on Fri Aug 21 2009 - 12:03:06 ART