No Multicast over Tunne?

[KGrev]

Hi,

I have an LTE router connected over vpn. I have a working gre tunnel within this connection. I can force traffic across the tunnel and load certain pages on a connected laptop on g0 interface. But instead I'd like to only use the tunnel for multicast traversal. Currently the router does see the distant end of the tunnel as a pim neighbor (ip - A.B.44.1), however, multicast isnt working. When I try to pull a feed I dont see any entries in the mroutes for the group. Also "debug ip pim" does not show any activity for the groups i try to stream just rp discovery for 224.0.1.40. Attached is a sample of the configuration of the router.

Any help is greatly appreciated.

[Harold Ritter]

Hi @KGrev ,

Is the IGMP membership report for mcast group 239.22.22.22 you see in Wireshark for IGMP version 2 or version 3? You might need to switch to version 3 on gi0 using "ip igmp version 3".

Regards,

[KGrev]

@MHM Cisco World @Harold Ritter  I think I figured it out. There was a control plane access list for CoPP Undesireable, These routers have to be stigged. However someone placed a block on a multicast range with the wrong subnet so it was blocking pretty much all subnets. I now see  igmp traffic and groups.

To future persons, CHECK YOUR CONTROL PLANE POLICIES

Thanks for your help!

[Harold Ritter]

I am glad you found the issue @KGrev and thanks for the feedback

[MHM Cisco World]

ip route C.D.236.254 255.255.255.255 Cellular0
!

 You use two static route for RP one via tunnel and other via cellular' 

And you use loopback as source' I am not sure if you need also ip pim under loopback use as source of tunnel or not' but I will check that 

MHM

[Harold Ritter]

Hi @MHM Cisco World ,

The "ip mroute" takes precedence over the "ip mroute" for RPF check. At this point though, the router will not populate the mroute with the mcast group if this mcast group is not seen in IGMP, so not even a PIM issue at this point.

Regards, 

[MHM Cisco World]

He never see any PIM neighbor'

So even if he have IGMP group there is no RP register this group with

MHM

[Harold Ritter]

Hi @MHM Cisco World ,

> He never see any PIM neighbor'

From the original post: "Currently the router does see the distant end of the tunnel as a pim neighbor (ip - A.B.44.1)"

> So even if he have IGMP group

You are trying to put the cart before the horse (i.e. get PIM to work before IGMP does). He has to see an IGMP membership report before anything happens at the PIM level. Without the group being present in IGMP, the mroute is not populated and PIM join can't be forwarded towards the RP.

Regards,

Regards,

[KGrev]

@MHM Cisco World @Harold Ritter  I have an important note. The timing couldnt be worse. The company allocated a SIM card to me for testing for a window. They just deactivated that sim. Thats why I lost my pim neighbor, my entire vpn is down.

I'll have to revisit this in a few days when they allow me to test again.

Thank you for your time @MHM Cisco World  and @Harold Ritter 

[Harold Ritter]

You are very welcome @KGrev .

BTW, you could continue troubleshooting the IGMP issue even if you don't have upstream connectivity.

Regards,