RC-AC68U - Media Bridge mode - Bonjour/ZeroConf/Multicast filtering?

[kris2k5]

Here's an interesting situation;

I just did a drop-in replacement of the RC-AC68U acting in Media Bridge mode using Merlin 3.0.0.4.376.49_4 as a substitute to my WUMC710 (Linksys) to bridge against my RT8000 (NetGear).

What I'm noticing is that ZeroConf/Bonjour/Avahi/mDNS is not propagating properly between the wired and wireless interface of the RT-AC68U.

I've isolated this using Bonjour Browsers at different points of the network, and the current hypothesis seems to point towards the RC-AC68U, and perhaps something either on vlan1 or eth1/eth2 affecting what's being bridged on br0.

Next steps is to figure-out how to get tcpdump/tethereal running on the router, and try to capture on each interface individually and isolate who is/not seeing the packets.

Insights appreciated as Linux bridging it not my forté.

Cheers

 

[alkie]

I'm having the same exact problem. I have two AC68Us, one is my main router, the other is in my living room acting as a media bridge.

TV/Stereo Receiver -> AC68U (media bridge) -> AC68U (Main Router) -> PC/Wireless devices

My stereo receiver supports airplay; however, it does not work when connected to the bridge, it only works when i connect it directly to the main router using wifi.

I did a packet capture and I notice that the MDNS query response from the Receiver does not reach the PC when running through the media bridge. I do see the response when i bypass the media bridge and connect directly using the built in wireless on the receiver.

I am also seeing similar issues with DLNA. The initial discovery works but it stops working after a bit.

This is pretty frustrating because i sold my ea6500 running ddwrt for this same exact reason.

Edit. I tried it using both the newest stock firmware and the newest merlin firmware. 3.0.0.4.376.49_4
Edit2 WDS is not an option, simply because of the huge security holes.

 

[Shelbrain]

I am having the same problem, albeit with different routers. In my case, the T-Mobile CellSpot (AC-1900) is the main router and the AC66U is the media bridge. I thought I was having a problem with my Yamaha receiver, but the DLNA server is recognized when connected directly to the main router, but is not recognized when it is connected via Ethernet to the media bridge. When connected via Ethernet to the media bridge, I still get music streaming via Pandora/Spotify etc (so there is internet connectivity) however it is not recognized via DLNA so I can't stream music saved on my main PC connected to the AC-1900. I hope I am not thread jacking, but wanted to report the same issue with the media bridge setup.

 

[alkie]

The only hope I see right now is the new firmware that asus announced. There is a discussion here: http://forums.smallnetbuilder.com/showthread.php?t=21632

 

[kris2k5]

Yeah, from reading through a lot of the Linux Bridging documentation, it appears to be related to the IGMP handling, but I'm not sure how just yet.

I've found some posts about disabling IGMP alltogether fixes the issue, others talking about activating the IGMP snoop, others about changing the IGMP version default from auto to V2 since by default it tries for V3), and nothing quite going.

Since I saw the new FW release posted, I figured its perhaps just best to wait-out the week until Asus releases the global version (according to the JP notes), and revert back from Merlin to the factory firmware.

In any case, its not like I'm using exotic features from the device in Media mode...

Cheers!

 

[alkie]

I have IGMP snooping disabled everywhere and that seems to help with it connecting but it still seems to be random. The problem could be with the linux library/implementation that these routers are using. I had the same problem with my ddwrt ea6500.

My plan is also to revert my bridge to the stock firmware once the new version is released. Hopefully that fixes it.

 

[alkie]

Anyone had any luck with the new firmware? It made no difference for me.

 

[Shelbrain]

Anyone had any luck with the new firmware? It made no difference for me.

I just upgraded to the new firmware tonight on the AC66U. My AC-1900 is connected via Ethernet to the modem and the AC66U is acting as the media bridge. My Yamaha receiver is connected to the media bridge via Ethernet and I was able to see my Windows 7 PC which is connected to the main router. This worked sporadically and not consistently on the old firmware. I will continue to play with it, but so far after doing several reboots of the modems, routers and Windows 7 PC everything is functioning as intended. I remain cautiously optimistic!

EDIT: Crap, I am getting the dreaded [no content] message on my Yamaha receiver which means that my the receiver connected to the media bridge is no longer recognizing the Windows 7 PC DLNA server connected to the main router. So it seems I am in the same boat as alkie.

 

[Deleted member 35370]

Hi,

If I understand wheel, you don't see your devices when connected in bridge mode? (sorry, english is not my first language).

I have Airplay dropping with my network setup, a RT-N56U in wireless bridged on the master RT-AC68U. My Yamaha (RX-A720) receiver have Airplay but not wireless, just rj45.

Bonjour/mDSN is for discovery device and translate name to IP? If I able to see my Yamaha on the network, but loss connection after a randomly time music streaming (itunes or Spotify), do you think it is the same problem of yours?

 

[alkie]

I'm sorry to hear Shelbrain, looks like asus didn't fix our issues after all.

malazaba, In media bridge mode it seems there is a problem passing IGMP traffic which is what allows the discovery of Airplay/DLNA devices. Once connected, the traffic is UDP unicast. So if you are seeing dropouts after the connection you may be experiencing a different or multiple problems.

 

[Deleted member 35370]

malazaba, In media bridge mode it seems there is a problem passing IGMP traffic which is what allows the discovery of Airplay/DLNA devices. Once connected, the traffic is UDP unicast. So if you are seeing dropouts after the connection you may be experiencing a different or multiple problems.

Ok, thank for the respond. Good luck kris2k5 and Shelbrain.

 

[Shelbrain]

I'm sorry to hear Shelbrain, looks like asus didn't fix our issues after all.

malazaba, In media bridge mode it seems there is a problem passing IGMP traffic which is what allows the discovery of Airplay/DLNA devices. Once connected, the traffic is UDP unicast. So if you are seeing dropouts after the connection you may be experiencing a different or multiple problems.

Hey Alkie,
Have you tried Merlin's firmware on your router? I really like the Asus firmware in every other respect so far but on a whim flashed my RT-AC66U with Merlin's latest build and my stereo receiver connected to the media bridge has been able to see DLNA information from the server connected to the main router. This was my goal since for the time being I am unable to run an Ethernet cable to this location. So far so food, fingers crossed! I did a backup of my settings as a precaution but changed no other settings on the router other than the firmware.

 

[alkie]

Dlna discovery works sporadically in one direction only. AirPlay is even worst. I tried merlins build but I had the same problems with it.

 

[Shelbrain]

Dlna discovery works sporadically in one direction only. AirPlay is even worst. I tried merlins build but I had the same problems with it.

My problems are returned as well. I was initially excited but the neither the stock Asus or Merlin's firmware appear to fix my DLNA issues when the media bridge is involved.

 

[alkie]

This is pretty frustrating. I don't know what else we can do at this point.

My problems are returned as well. I was initially excited but the neither the stock Asus or Merlin's firmware appear to fix my DLNA issues when the media bridge is involved.

 

[PabloAbonia]

I would suggest igmp snoop with devices, as well as doing doing proxy on the iptv page. I would also suggest enabling the spanning tree protocol., under LAN ->Switch control. Also assuming that their are dumb hubs rather than smart switches, you may wish to upgrade to a switch that would allow snooping to be guided by the router. So long as the the bridge is on the same subnet this should work. The bonjour data can not cross subnets, (192.168.1.0 >X< 192.168.2.0) in most cases unless special efforts are made to allow it, typically in higher end devices.

The bonjour service is prone to generating "network storms" which you can see on the event viewer on windows machines. This could be responsible for the erratic behavior you are seeing.


--
Pablo

 

[PabloAbonia]

Also, you should probably completely unplug ALL of the AirPlay devices including Apple TV and machine running iTunes. The AirPlay devices have a habit of maintaining outdated information in my experience.

A good description of the problem can be found by searching for Xirrus Bonjour Director on any websearch, or reading the PDF from the site here:

http://www.xirrus.com/Products/Network-Management/Network-Services/Bonjour-Director

I am not advocating its use, and I am not linked to this company. However they do provide a good description of the underlying problem that can be downloaded from that page.



--
Pablo

 

[marcusb]

Try disabling multicast_snooping:

echo "0" > /sys/devices/virtual/net/br-lan/bridge/multicast_snooping

On openWRT you put this in rc.local.. maybe put it in init-start?

This fixed a upnp issue with my Xbox 360 on a client bridge running OpenWRT. I changed the path to be correct for the AC68.

 

[kris2k5]

Try disabling multicast_snooping:

echo "0" > /sys/devices/virtual/net/br-lan/bridge/multicast_snooping

On openWRT you put this in rc.local.. maybe put it in init-start?

This fixed a upnp issue with my Xbox 360 on a client bridge running OpenWRT. I changed the path to be correct for the AC68.

Nada; tried that one a long while back; this is getting frustrating! Ideas? Bonjour proxy?

 

[Bloody]

Any ideas about how to make multicast over WiFi working? Found info about next fix:

- Fixed reserved, upnp/ssdp, mdns mcast pass-through with 2.4GHz/5GHz band IGMP snooping(AirPlay and AirPrint connection issue resolved).

But this fix is for DSL-N55U beta firmware v3.0.0.4.228.
Tried all available firmwares for AC68U like Merlin (and Fork), Tomato, DD-WRT. Still can't wake my Apple TV through AirPlay from iPhone. It working only few minutes after router reboot(or if Apple TV waked up through remote).