IPTV issue with multi-floor building and Catalyst 9300s

[wsalomon75]

Hello all,

Here is my setup:
1st Floor: ISP IPTV Connection > Catalyst 9300 >

2nd Floor: Catalyst 9300 >

3rd Floor: Catalyst 9300 > Catalyst 9500 > 6807 Core

I'm currently having issues with the IPTV not working on the second/third floors of the building. When a set top box is placed on the 1st floor directly connected to the ISP device, it works. I have set up a VLAN 125 for this specifically, and have added the following to all 3 floors: #>ip igmp snooping

On the core, I have added:

#>int VLAN 125

#>ip pim sparse-mode

#>ip igmp version 2

#>ip igmp snooping

Running a test on the second floor, I get nothing. I don't have a IPTV server or anything. Could this be the issue? Am I missing something?

[Turn2]

Oh - should have reiterated that each VLAN also needs an IP address assigned as multicast needs an accurate underlying unicast route table in order to function properly. This normally goes without saying, but I think you mentioned that you didn't have an IP address on your VLAN 125 before.

[wsalomon75]

Thank you for the reply! Question for you though. We have a phone system warning system that uses multicast, and all of the VLANs already have #>ip pim sparse-mode on them. Would doing this affect that at all? Would the traffic from the IPTV slow down traffic in those VLANs not using it since they are now listening for it?

[MHM Cisco World]

@Turn2 ask wonderful Q'

Are multicast source and multicast reciever in same subnet or not?

I assume that ISP connect and provide multicast is in same vlan as receiver.

MHM

[wsalomon75]

Well, yes. So the ISP is providing the IPTV Router, which is providing a 192.168.1.0/24 address. I plugged that directly in to the switch at floor 1, on a port that is on VLAN 125. VLAN 125 has no IP address, so in theory, anything connected to that VLAN should get an IP in that 192.168.1.0/24 subnet that is provided by the ISP, so long as it's trunked up to the other switches on the floors, right?

Edit: I tested the connection by also connecting a IPTV set top box on the second floor to a port connected in the 125 VLAN (it gets a 192.168.1.0/24 address) but get no picture.

[Turn2]

If VLAN 125 doesn't have an IP address assigned to it, then it isn't in your unicast route table, and multicast will fail. You need an IP address on that VLAN.

[wsalomon75]

Stupid question here. If the ISP is handing out 192.168.1.0/24 addresses with it's router that's connecting to the port on VLAN 125, and I assign VLAN 125 an IP of say 10.10.125.0/24 at the Core, wouldn't that conflict?

[Turn2]

You want to have a 192.168.1.x/24 address on VLAN 125 on your core. PIM (multicast) routing uses something called Reverse Path Fowarding (RPF) - essentially when the core receives a multicast packet on a VLAN, it looks in it's unicast route table for a route matching the source address of the packet. If no unicast route exists, it will drop the packet. So give VLAN 125 some address outside of the DHCP range your ISP is handing out (or try just using something like 192.168.1.254/24 to be safe) and everything should be fine.

[Turn2]

Famous last words - "It shouldn't affect the existing traffic".

It's hard to be sure without looking at the configuration of the 6807 - can you post it? Also, post the results of "Show ip mroute" if possible.

[wsalomon75]

Sorry for the late response, things have been busy here! Quick question for you. Does the IP address of the VLAN 125 HAVE to be a 192.168.1.0/24 address or can it be anything?