Roon Arc cannot communicate with Qobuz via TailScale (ref#50XIJX)

Support
1

Hi! What’s not quite right with Roon?

· Can’t reach my Server, remotes or ARC

Can’t connect to my Server, remotes or ARC

· Other ARC issues

Tell us what's going on

· Cannot reproduce Qobuz content via Roon Arc: display message "problem communicating with Qobuz". Other contents (Tidal) are reproduced correctly. Qobuz contents are reproduced correctly with Roon in local home network. I'm using Roon Core with Rock (Version 2.1 (build 271) production) and Roon Arc on Iphone XR, IOS version18.7.9. I use Starlink as home internet provider, so I use TailScale service to esablish communication betweern Roon Arc and Roon server.

Tell us about your home network

· Starlink as Internet provider, TailScale service to make communication between Roon Server and Arc

2

Hello, I’ve just read the following post …

So why did this happen to me again in July?

I’m from Italy. Thanks

3

Hi @lorenzovecchi ,

Welcome to the forum!

Just to confirm this aspect, ARC is able to play Qobuz content when you’re on your home network, and the issue only happens when you’re on-the-go and using Tailscale?

The way that ARC works is that it creates a direct connection to the streaming services for playback, whereas the regular Roon app has everything processed by the Roon Server for playback first.

4

Hi Noris, thank you.

Obviously I never use ARC when I’m in my home network, in this case I use regular Roon app and everything works fine (also Qobuz streaming). The issue appeared with Roon Arc on my Iphone outside my home network for the first time in these days, Iphone connected to 4g cellular network, Iphone and Rock connected to Tailscale. Until now I’ve always used Roon Arc on my Iphone connected to 4g network and Tailscale without any problem.

5

As suggested I’ve just tried to use Roon ARC app in my home network (without Tailscale): actually in this situation also Qobuz streaming work fine, then the issue only happens when I’m on-the-go using Tailscale.

6

Hey @lorenzovecchi,

Thanks for confirming that, it’s a really helpful detail.

Based on this, the key question is which network path that direct Qobuz connection is taking when you’re out and about.

The main thing to check is whether Tailscale has an exit node enabled on your iPhone:

  • If it's off, ARC only uses Tailscale to reach your Server, and the Qobuz stream goes out over your normal 4G connection.
  • If it's on, all of your iPhone's internet, including the Qobuz stream, is routed back out through your home Starlink connection.
If the exit node is on, your Qobuz traffic is effectively leaving through Starlink, and Starlink's shared/CGNAT addresses can get caught by Qobuz's traffic-filtering rules. Tidal doesn't apply the same filtering, which would explain why Tidal plays fine but Qobuz doesn't, and why everything works at home, where the connection leaves your network differently.

Could you try the following?

  1. Open the Tailscale app on your iPhone and check whether an exit node is enabled. ARC doesn't need one, it only needs Tailscale to reach your Server.
  2. If an exit node is on, turn it off (keep Tailscale connected) and try Qobuz in ARC again on 4G.
  3. As a quick sanity check, open a browser on the same iPhone and visit a "what's my IP" page with the exit node on vs. off, this shows whether your traffic is leaving via Starlink or your mobile carrier.
If Qobuz starts working with the exit node off, we've found it. If the exit node was already off and it's still failing, let me know, in that case we'll look at a possible MTU issue with Starlink + Tailscale, which can trip up Qobuz's higher-bandwidth streams specifically.

Also, when it fails: is it every Qobuz track, or only certain albums? And is it consistent or does it come and go?

7

Hi Benjamin, thanks for looking into this.

One important correction first: I don’t have an exit node configured at all. My tailnet contains only two devices, my iPhone and the ROCK, and the ROCK can’t act as an exit node — RoonOS only exposes a basic Tailscale login, with no way to advertise it as one. So Tailscale is only routing the 100.64.0.0/10 range so ARC can reach the Server, and ARC’s Qobuz connection already goes out over my normal 4G connection, which is the configuration you’re describing as the fix.

To be precise: the Tailscale app on my iPhone doesn’t even offer an exit node to select. The only option under Exit Node is “Run as exit node”, which would advertise my phone as a gateway for other devices — the picker for using one doesn’t appear because no device in my tailnet advertises itself as an exit node.

I ran your sanity check: with Tailscale connected or not on 4G, a “what’s my IP” page shows the same my mobile carrier’s address (93.34.48.20), not my Starlink address.

I also don’t think the Starlink CGNAT theory fits my results. When I use ARC on my home Wi-Fi, its Qobuz traffic leaves through exactly that Starlink CGNAT address, and playback works fine. If Qobuz were filtering that range, ARC at home should fail too.

Here is everything I’ve tested so far:

Network App Tailscale Qobuz playback
4G Qobuz native app connected works
Home Wi-Fi Roon ARC connected works
4G Roon ARC connected, no exit node fails

Disabling Tailscale’s DNS on the iPhone made no difference — the error is identical with it on and off.

So the only combination that fails is ARC requests leaving from my mobile carrier’s network. Same account, same Server, same app working from a different network. That looks much closer to the April pattern, where ARC-specific requests were caught by Qobuz’s filtering rules depending on the network they came from.

On MTU: since ARC’s Qobuz connection never enters the Tailscale tunnel in my setup, I don’t think that applies here either. It would become relevant only if I actually set up an exit node — which I’m happy to try as a test if you think it would tell us something useful.

To answer your last questions: every Qobuz tracks and every album fail (both HiRes and CD quality) and it’s consistent.

Thanks.

8

Quick follow-up on my previous post.

Since I had no exit node at all, I set one up deliberately, as an experiment, to see what would change. I installed Tailscale on a Windows PC on my home LAN, advertised it as an exit node, approved it in the admin console, and then selected it on my iPhone while on 4G. I confirmed with a “what’s my IP” page that websites now see my Starlink address instead of my mobile carrier’s.

Result: Qobuz plays in ARC without any error.

So the direction is the opposite of the hypothesis. Routing ARC’s traffic out through Starlink is what makes Qobuz work; leaving through my mobile carrier’s network is what fails. The only variable that changed is the public IP the request comes from — same account, same Server, same track, same app version.

I think this also rules out MTU: with the exit node active, the Qobuz stream now genuinely travels inside the Tailscale tunnel on top of Starlink, and it plays fine. Before, without an exit node, that stream never entered the tunnel at all.

For completeness, the full matrix:

Network App Tailscale Qobuz playback
4G Qobuz native app connected, no exit node works
Home Wi-Fi Roon ARC -– works
4G Roon ARC connected, no exit node fails
4G Roon ARC connected, exit node via Starlink works

My mobile carrier is Fastweb. If Qobuz’s filtering rules work on IP ranges or ASNs, that’s probably the detail worth passing on to them.

I’m treating the exit node as a temporary workaround rather than a permanent setup — it forces all my phone’s traffic through my home connection and depends on a PC staying awake. Happy to run any further test or provide logs if it helps narrow this down on the Qobuz side.