Troubleshooting Native Synology Package not binding to OS-Level Tailscale interface with subnet routing

Channels DVR Server
#1

Title: Native Synology package not binding to OS-level Tailscale interface (subnet routing)

Setup:

  • Channels DVR Server (native Synology package, not Docker) on a Synology DS418
  • DS418 also runs Tailscale as a separate OS-level Synology package, functioning as a subnet router advertising my home LAN (172.16.70.0/24) for weeks without issues
  • Remote sites (two locations) connect via their own local Tailscale subnet routers, routing into my home network over Tailscale — this setup already works for every other local service

Problem:
Devices without a Tailscale client (Fire TV Stick and Sony TV's specifically) at remote sites cannot reach Channels DVR Server on port 8089, even though:

  • Ping to the DS418's LAN IP succeeds perfectly from the remote site (0% loss)
  • The remote site's firewall rules and static routes are confirmed correct via packet capture (tcpdump shows the SYN packet successfully leaving the remote subnet router into the Tailscale tunnel)
  • Devices that ARE running Tailscale directly (phone, laptop) connect to Channels perfectly fine from the same remote locations

Diagnosis:
Settings → General on the Channels admin page shows: "Advertising [hostname].local via 1 network: [LAN IP, link-local IP]" — it never lists the Tailscale interface, even after a full Synology reboot. Enabling HTTP Logging and retrying confirms zero incoming requests ever reach Channels from the remote subnet — the connection attempt never reaches the application layer at all.

Already ruled out:

  • Firewall rules (added explicit allow rules, still fails)
  • Sophos ACLs and Tailscale ACLs (tested maximally permissive rules, still fails)
  • DSM's own firewall (confirmed disabled)
  • Full reboot of the Synology (no change to the "1 network" detection)
  • Channels' own embedded Tailscale toggle (unrelated — it's a separate identity from the OS-level Tailscale, toggling it on/off makes no difference)

This looks like it may be the same "wrong Tailscale device" detection issue mentioned by a developer in the 2022 experimental Tailscale integration thread. Is this a known limitation of the native Synology package specifically, and is Docker required to properly bind to all host network interfaces? Any workaround for the native package would be appreciated.

#2

I think you are saying that you are running Tailscale on you NAS as an exit node. That it's working for everything except Channels DVR. You have not enabled Tailscale in Channels DVR.

It sounds like you need a route too your exit node on your Channels DVR. Is that even possible? A possible workaround is to place a static route on your router pointing to your exit node.

I stopped using Tailscale and instead use a traditional VPN running on my router as I got tired of all the side effects of Tailscale.

#3

Welcome to the Channels Community @DLH757!

I assume your post was generated by AI, but if I'm understanding your issues correctly:

  • You have remote devices that have no Tailscale client available, so you'd like to use a subnet router.
  • Your Channels DVR server is running on your local LAN, and its host Synology NAS is running Tailscale.

In order for this to work, I believe you need to have a Tailscale subnet router running on the remote LAN. That's the gateway for remote devices, that only have LAN IPs on that remote LAN, to access your Tailnet.

EDIT: A static route on the remote router may also be required.

#4

It's easiest to install Tailscale on the remote client. One can even do this locally to test if Tailscale is working or do it on your phone and come in via the carrier network.

Also, with Tailscale on the client, he should be able to ping the server.

#5

Yes as i mentioned in my post i have a tailscale subnet router advertising routes at each end and all ports are allowed and i can ping the synology from my lan both with tailscale connected and without. I also have a static route that resolves properly I can see the traffic hitting the synology on the logs which is also my tailscale router this setup has been working perfectly at multiple locations for months now. However the synology which is hosting the channels server never sees the tailscale interface of traffic. Any device that has tailscale directly on it can access my recordings. By the way this post is my own however i was using ai to help troubleshoot for over 6 hours and we both tried everything we could think off. I have been involved in IT work for over 20 years and was wondering if the issue from 2002 with respect to the synology software for the channels dvr server ever had the previous issue corrected.

Thanks!

#6

Since it used to work, what has changed recently? Any firmware or software upgrades?

If you have another 24/7 node on your network, you might want to try the Tailscale end node on it rather than the NAS. This avoids routing within your NAS which appears to me to be the place where the issue lives.

#7

If you just recently update TailScale on your Synology, it may need a reboot.