we use RB2011 routers to deliver multicast TV to the customers. Between STB’s and router is RB250/260 switch. Port 1 is connected to the router, and there is ACL rule to filter out multicast from port 2 and 3. Port 4 and 5 is for TV, and allow multicast to pass. Everything works fine, until user buy a modern WiFi router. Almost any brand, TP-Link, Linksys, Buffalo, Engenius, whatever. After configuring it like a bridge (wan is unplugged, DHCP server off) and connect any of the LAN ports to number 2 or 3 port (where multicast is filtered out) of the RB250/260 switch then after some time (30s or so) RB2011 will stop forward any multicast traffic to that port. After removing WiFi router, and disconnecting and reconnecting cable from specific port of RB2011, multicast will resume.
So I did some testing, set up Wireshark and etc. After some investigation, I did make another ACL filter to prevent forwarding any multicast traffic what come from WiFI router. Everything was fine and TV channels played forever. Well, WiFi router (in this case TL-WR741ND) will send out 2 type of multicast packets. One in pack of 13 is SSDP to address 239.255.255.250 and another is like Wireshark describe it - “V2 membership Query, general” to address 224.0.0.1. I discovered, that when filter out those packets, then problem disappear. On wifi routers is impossible to switch off those packets, even with third party firmwares like DD-WRT.
In conclusion, single packet from almost any SOHO WiFi router will kill IGMP proxy on MT router. All streams is still listed on the MFC table, but no traffic. Other interfaces with different subnets is not affected. Filtering out those packets in switch or ROS input rules will resolve the problem. I tested ROS versions 5.19-5.26 and 6.1-6.3, also several other MT routers (RB450G, RB750G).
Packet is described by wireshark like this:
[IGMP version: 2]
Type: Membership Query (0x11)
Max response time: 10,0 sec (0x64)
Header checksum: 0xee9b (correct)
Multicast address: 0.0.0.0 (0.0.0.0)
any similar experiences or comments?