IGMP Proxy Issues



  • Hello,

    I have been experiencing a really strange problem. When i activate IGMP Proxying for my IPTV service it causes my wifi to be extremely spotty. Here is the documentation regarding IGMP Proxying that i have reviewed: http://pfsensesetup.com/igmp-proxy-configuration-in-pfsense/

    If anyone can give any insight to this that would be awesome.

    Thanks.

    EDIT: i believe it has something to do with the way pfsense handles multicast traffic, but i am not sure what to do about it.



  • Do you have your IPTV box connected to the router via wifi? The wifi may then be saturated with the multicast traffic. This cannot be avoided by any router. Better connect the IPTV with an ethernet link then.

    Do you have a wifi adapter built into the pfsense machine? I would expect that pfsense as a router can recognize whether IGMP join- or leave-requests have been received over a link and therefore be able to restrict multicast traffic to specific links. I did not deal with this in pfSense yet however so I cannot answer this …

    Depending on the layout of your LAN an IGMP aware switch can solve the problem: These can recognize over which link multicast traffic must be sent. For this a switch is required to do "IGMP snooping" to recognize the join- and leave-requests of hosts to or from multicast groups.

    So if you have a switch connected to your pfsense machine and the IPTV as well as your wifi adapter are connected to this switch then replace this switch with an IGMP aware switch and the problem should be gone. This solution is independent from pfSense and works for me.

    Hope this helps.

    -flo-



  • Thank you for your reply. The STB is not connected via wifi, it is wired. and my wireless is broadcasted by a separate AP, not the pfsense box.

    That does give me an idea about my switch though. I will look into my Zyxel GS1910 switch and igmp snooping.



  • Is the wifi on the same subnet as the IPTV client? Multicast works a bit like broadcasts, meaning, every device on the subnet that the IPTV box is on, will receive the traffic, including wifi hosts (Most cheap APs nowadays just logically bridge the wired connection with the wifi radio, so wifi will be on the subnet that the AP is wired to)

    If this is the case then you need to move wifi to a different subnet, or have some multicast filtering done on the AP (i believe dd-wrt can do this)



  • It is on the same subnet, and i need it to be on the same subnet for other reasons. I have a DAP-2553 AP, i will have to look into multicast filtering with it.



  • Turned on IGMP Snooping on my Zyxel GS1910 switch and on my DAP-2553 Wireless AP. I haven't seen the problem come up yet. So far so good.

    Thanks for your help, everyone.