IPTV multicast from ISP VLAN to default VLAN

[nknezevic]

Hello everyone,

I’m working on an IPTV + Internet integration project for a hotel network, and I'm stuck on enabling multicast forwarding between an IPTV VLAN delivered by the ISP and my internal LAN VLAN.

I would highly appreciate any guidance or clarification, because I’m not fully sure whether I'm dealing with a configuration issue on my Catalyst 3850 or a limitation on the ISP side.

Setup summary:

ISP provides IPTV on VLAN 3200 (multicast only)
Internet arrives on different VLAN (handled by ASA5506 that is working behind the switch)
My goal is to allow IPTV multicast from ISP VLAN to be forwarded to default VLAN 1 on 3850
STBs/TVs are connected on default VLAN and receive IP address from ASA DHCP pool and internet works perfectly in default VLAN
Multicast IPTV streams don't cross from ISP VLAN into default VLAN.

What I already did:

• enabled IP multicast-routing globally
• enabled PIM sparse-dense-mode on default VLAN and ISP VLAN
• created static default route towards ISP router
• IGMP joins on default VLAN are visible
• PIM DR election happens on ISP VLAN but I only see *,G and never S,G
• no PIM neighbors on ISP VLAN
• IPTV traffic never appears on default VLAN

My question is, is it possible to forward multicast from L2 ISP VLAN into routed VLAN on Catalyst 3850 or does this require the ISP to support L3 multicast on their end?

This is the first time I'm working with multicast configuration, and any help or advice would be greatly appreciated. My running-config is attached bellow.

Thank you in advanced!

[Ben Weber · Accepted solution]

Hey @nknezevic 

The problem is that the 3850 cannot build the RPF path with the upstream L3 PIM neighbour as it cannot discover the source from VLAN 3200 (which is why you only see *,G and never S,G).

If the ISP is providing a L2 IPTV access, they expect your receivers to reside in the same VLAN as the IPTV feed so that IGMP members are visible to the source. 

You will need to bridge the multicast traffic across VLANs in order for it to work appropriately. Typically you would use Multicast VLAN Registration (MVR) to achieve this but I am not sure if it is supported on the 3850 (see Multicast VLAN Registration -MVR with catalyst 3850 - Cisco Community).

If MVR is not supported, you may have to reach out to your ISP to see if they support L3 multicast.

Good luck! 

[nknezevic]

Hello @Ben Weber, I replaced 3850 with different switch that supported MVR. After that and reading how to configure it, It works now. Thank you so much for your help!

[Joseph W. Doherty]

Have you tried https://www.cisco.com/c/en/us/support/docs/ip/ip-multicast/119383-technote-ip-multicast-00.html, assuming your router has an interface where the multicast is being delivered to you.

[nknezevic]

Hi Joseph, I tried it and it didn't work. But like it was suggested, I configured MVR and everything works now. Thank you for your suggestion and help!