[c-nsp] Multicast group but no traffic

[Scott Voll]

Why would I see this on my WAN router?

(*, 225.5.5.5), 02:02:57/00:03:29, RP 10.255.255.2, flags: S
  Incoming interface: GigabitEthernet0/0, RPF nbr 10.0.1.3
  Outgoing interface list:
    GigabitEthernet0/1.902, Forward/Sparse, 00:42:16/00:03:29

if I have an incoming and outgoing interface shouldn't I see an SC flag?

TIA

Scott



On Sat, May 10, 2014 at 12:20 AM, Vitkovský Adam <adam.vitkovsky at swan.sk>wrote:

> Well talking multicast you need to specify what route (state) are you
> seeing as well as which PIM mode are you running across your WAN.
>
> So you see either just the (*,g) state -means the designated router for
> the LAN segment as displayed by the cmd: " sh ip pim int" (Nexus) has
> translated the IGMP membership reports(igmp joins) into PIM Joins and sent
> them towards the RP (would be good to know which of your routers is RP).
> You might actually be getting the stream if PIM is running in BIDIR or
> Dense mode -the stream can be checked via "sh ip mroute active".
>
> Or you see also the (s,g) state -means the RP has an active source for the
> previously requested group or has send a register message towards the
> source.
> In either case as the source starts to send traffic down the shared tree
> (*,g) this is how the Nexus will learn about the source of the source for
> the group and can join source tree by sending PIM Join towards the Source
> (s,g) state.  -the stream can be checked via "sh ip mroute active".
>
>
> adam
> > -----Original Message-----
> > From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
> > Scott Voll
> > Sent: Friday, May 09, 2014 9:38 PM
> > To: Phil Mayers
> > Cc: cisco-nsp at puck.nether.net
> > Subject: Re: [c-nsp] Multicast group but no traffic
> >
> > VLC Player with TTL 10.  Connected to 3560 to Nexus 55xx with Layer 3.
> >  connection to 3845 over WAN to remote site, to 2911 to 2960 layer 2
> switch.
> >
> > I can see on Nexus, 3845 and 2911 the IP Mroute for the group I'm
> sending.
> >  Via a packet capture I can see the multicast local to the Nexus on
> multiple
> > vlan's
> >
> > I can see on the 2960 the groups and interfaces.  But a wire capture on
> the
> > local PC all I see is the join packets, no traffic.
> >
> > Other ideas?
> >
> > Scott
> >
> >
> > On Fri, May 9, 2014 at 11:28 AM, Phil Mayers
> > <p.mayers at imperial.ac.uk>wrote:
> >
> > > On 09/05/2014 18:53, Scott Voll wrote:
> > >
> > >> I'm working on rolling out my Multicast across my WAN.
> > >>
> > >> I can see the Multicast group on the WAN router and I can see it on
> > >> the switch interface, but I'm not getting the traffic.  What should I
> > >> be looking at?
> > >>
> > >
> > > That's a bit vague. John has made some good suggestions but you'd get
> > > more specific answers if you can specify the topology in detail.
> > >
> > > How are you determining you're not "seeing" the traffic? No video at
> > > receiver app? If so, check again with tcpdump/wireshark and look out
> > > for software firewalls. That one catches me a lot - I always forget
> > > iptables on my laptop :o(
> > >
> > > "sh ip mr active" and "sh ip mr count" are useful at L3 hops. L2 hops
> > > are far harder to debug, unfortunately.
> > >
> > > _______________________________________________
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> > >
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