Emby 4.8.11.0 on TrueNAS CE 24.10.2.2 does not find DLNA media device

[KneelBeforeZod 13]

Emby debug and hardware detection logs attached.

Tested with:
- Emby Server 4.9.1.5 beta on TrueNAS CE 24.10.2.2 - does not find DLNA media device
- Emby Server 4.8.11.0 on macOS 12.7.4 - does find DLNA media device (fresh install, all defaults)
- Emby Android app 3.4.74 - does not find DLNA media device
- Primare NP5 Android app - does find DLNA media device

Other information:
- Firewall/router is pfSense CE 2.8.0-RELEASE (amd64)
- Cisco SG300 switch
- 192.168.0.0/16 network; no VLANS; just this one (large!) subnet
- From TrueNAS, both NP5 and Emby server can be pinged (pinging from within Emby Docker container not possible due to "permission denied" despite being root)
- All tests done with computers on the same network
- Everything else on the network seems to be fine
- No error messages from Emby

This whole setup used to work fine, but I haven't listened to music through this system for a few months and in that time there have been several Emby on TrueNAS updates.

 

 

Emby debug server logs (TrueNAS - not working).txt Emby hardware detection logs (TrueNAS - not working).txt

Emby debug server logs (macOS - working fine).txt Emby hardware detection logs (macOS - working fine).txt

Edited July 12, 2025 by KneelBeforeZod

[Luke 42078]

HI, do you have the truenas container set to host or bridge networking mode? host mode will make it a lot easier to get this function working.

[KneelBeforeZod 13]

Hello Luke.  When I select "Host Network", the fields for setting the HTTP/S ports disappear so there's no way I know of to open Emby in a browser to check whether it's discovered the NP5.  That's for my test Emby server on TrueNAS.

The other Emby server (for which DLNA was working, also on TN) is set to have its own IP address but when I select "Host Network" the fields for the port numbers disappear.

Not sure where to go from there.

[Luke 42078]

I would try host network anyway even with those fields disappearing. that just means you have to configure that on the host system.

[KneelBeforeZod 13]

How interesting - that worked!

So, in the app config on TrueNAS, I selected "Host network" and then used Portainer to look-up the correct port which is of course the default: 8096 (I'd forgotten).  I could then access Emby using the TrueNAS host IP but on that port - just like I always did before TN's per-app IP feature landed (which I guess is bridge networking mode).  With some Nginx config, Emby can be accessed by hostname again.
 

2 hours ago, Luke said:

host mode will make it a lot easier to get this function working.

Presumably this is to do with the change of network isolation between Docker container and Docker host (from host mode to bridge mode) as a result of the per-app feature.  How can this DLNA discovery be made to work while still using bridge mode?

[KneelBeforeZod 13]

I'll answer my own question here.  The AI Gods answered the question "does docker bridge network support multicast?"

"Docker's default bridge network does not natively support multicast. While the underlying Linux bridge can handle multicast, Docker's default network setup and how it interacts with Linux kernel multicast routing present limitations. However, multicast can be achieved using other networking options like host networking, macvlan, or by using workarounds like running a multicast routing daemon"

So DLNA, which requires multicast support, will never work over the Docker bridge network driver.  Other methods such as macvlan could be made to work but that's more aggro that I want!  For now, the music is playing and that's all I wanted.

Thanks for your help Luke!  I did try finding out the answer before posting on here but I didn't know enough to search for the right thing.

Edited July 12, 2025 by KneelBeforeZod