AC66U Blocking incoming SSDP packets

[scope021]

I have 2 RT-AC66U's, one in Router mode ("Router"), the other in Media Bridge mode ("Media Bridge"), both running 3.0.0.4.270.26 Merlin build. They are connected to each other on the 5ghz band. No other devices use this band/connection. I have several upnp/dlna media servers running on different machines connected to my network. If I'm connected to the AC66U that is in Router mode on the 2.4ghz band or wired, I can discover the upnp/dlna servers that are also connected to the Router, but not those connected to the Media Bridge. However, if I'm connected to the Media Bridge on it's 2.4ghz SSID (or wired), I can see/discover all of the upnp/dlna servers on my network, including those connected to the Media Bridge (both wired and wireless), as well as those connected to the Router.

If I'm connected to the Router (wired or 2.4ghz), I can only see the upnp/dlna servers that are connected to the Media Bridge (wired or wireless) if I manually reset the upnp/dlna servers, or wait for them to send out a ssdp packet (15 minutes or so).

Thus, it appears that one of my RT-AC66Us (probably the Media Bridge?) is blocking incoming SSDP packets, making the upnp servers connected to it undiscoverable.

I have tried both the .270 and .354 stock firmware, as well as the above mentioned merlin build, and they all have this problem. I have reset to factory defaults and reconfigured several times. I've disabled the built-in media servers on both routers, but that didn't help either.

How can I force the router not to block incoming SSDP packets? Is this a known issue or do I have a defective unit?

 

[RMerlin]

Known issue. Nothing I can do about it.

 

[scope021]

Thanks, RMerlin. Finally a real answer to my question. I've asked ASUS support numerous times whether this is a known issue, and no one knew what I was talking about. What's the point of a "Media Bridge" if it's going to block your media servers from being discoverable???

 

[RMerlin]

This is probably related to the discussion here:

https://github.com/RMerl/asuswrt-merlin/issues/164

 

[alleinherrscher]

Sorry to reanimate this old topic. But is there any solution to the problem described above?

I'm running an ASUS RT-AC66U with stock firmware 3.0.0.4.376_3861 in the "Media Bridge" Mode, connected via WIFI to an ASUS AC3200 which acts as access point and is connected by cable to a router of my ISP. IPTV runs beautifully, when i use a media receiver, connected via cable with the RT-AC66U bridge.
So IGMP Snooping seems to work fine?!

However, the media-receiver behind the AC66U does not find the other media-receivers within my network, so i cannot access movies, that are stored on those receivers from the media-receiver connected to the AC66U.

I scanned the SSDP communication between the media-receivers using wireshark and noticed that all receivers communicate via 239.255.255.250 with alternating source port and 8082 as destination port. I also figured out, that the TTL of those packages is 1, but trying to increase the value via iptables didn't really help. However, incoming UDP-Broadcast packages seem to be blocked by the AC66U.

Is there anythink that i can modify in the iptables/igmp-proxy/bridge configuration to let ssdp packages pass the bridge?

Thanks in advance,
Michael