Roon Arc unavailable after moving to Switzerland (Salt router)

[David_Flynn]

Roon Server Machine

Core Machine

NUC8I5BEH3 I5-8259U, Samsung 250GB 970 M2, 8GB DDR4, ROCK installed

Network Details

NUC connected by Ethernet to ethernet point in a room that is directly connected to the main Router, a Salt FibreX6.

Library Size

10500 tracks (connected to NUC by USB to a 4TB external SSD)

Networking Gear & Setup Details

Ethernet connection in wall that directly connects to the router in a basement room.

1. Who is your internet service provider?
   Salt.ch

2. Please list the make and model of your modem and router?
   Fibrebox X6.

3. Do you have any additional network hardware, like additional routers or managed switches?
   There are two Wifi extenders in the house that are connected to the router in the same way - each room as a ethernet point which can be connected at the router.

4. Does your network have any VPNs, proxy servers, or enterprise-grade security?
   I’m not sure.

Connected Audio Devices

None at the moment as just moved house and setting up, but will be KEF LS50 ii.

Description of Issue -

What is the exact port forwarding error message you see in the Roon Settings → ARC tab?

So I’ve just moved from the UK to Switzerland and my Roon Core/Arc worked perfectly in the UK. Today I managed to plug into my NUC into one of the ethernet ports that is connected to the central router. To get Roon to work on the network, I had to create an IO reservation on the router admin - this screenshot:

This has meant I’m able to access the server okay from my laptop and iPad. However I’m struggling getting Roon Arc to work. I switched on the DHCP option, and then have tried to create a specific port forwarding on this screenshot:

However as you can see on this, it’s not working:

I’ve seen a previous thread saying that the way Salt sets up the broadband here, it’s impossible to be able to connect. But it seems that since this thread it has opened up the possibility of port forwarding.

With my NUC working perfectly in the UK (I previously had port forwarding challenges with Virgin but got it to work), I am assuming it’s a Salt network challenge, not my NUC. Any help would be appreciated.

The previous thread in Sept 22 said that:
Salt. Mobile SA has widely implemented IPv6 addresses for their residential accounts and uses CG-NAT for that tier. It does not appear that they have a DS-Lite IPv4 tunneling option or PCP support that will allow for Salt. users to either automatically or manually configure port forwarding. So, ARC is limited to home network use and playback of offline downloaded content at this time.

[David_Flynn]

I’ve noticed on the Firewall that this option now exists, could this help? If so, what do I add? I’ve attempted the attached

[connor]

Hi @David_Flynn,

The workaround described in the above thread is only possible if you have both a local network setup and a particular Salt account that supports true dual-stack. You’d effectively disable IPv4 and create an IPv6 firewall “pinhole” that permits up- and downstream traffic from the IPv6 address assigned to your RoonServer. This would be within the IPv6 Firewall settings of your router, rather than the Port Forward section. However, this process is quite error-prone and tedious and could potentially disrupt Roon’s ability to communicate with other local networked devices, depending on their networking capabilities.

Since you have a ROCK, I’d instead try setting up Tailscale. It’s a simpler and more reliable setup for traversing network address translation layers than trying to configure end-to-end IPv6. This bypasses port forwarding entirely by safely creating a proxy-mesh VPN connection between your phone and the NUC. Here’s a quick guide:

Tailscale Setup Instructions: Nucleus Titan, Nucleus One, and ROCK

[David_Flynn]

Hi Connor,

That is hugely helpful, thank you. Due to the age of my NUC (built in 2020), I had to change the BIOS to boot with UEFI and then reinstalled ROCK to the latest version (before then registering with Tailscale).

Last night when I removed my phone from WIFI, all worked with Roon Arc, however on leaving my house this morning, it’s saying it can’t find the Roon Server (but the cloud connection is good). I’m not sure why so will check when I get home.

[noris]

Hi @David_Flynn ,

Thanks for the update, please let us know when you’ve had a chance to look into this further after getting home, thanks!

[David_Flynn]

Hi,

Thanks for checking in - I logged on when I got back and rebooted the server (just in case). Roon within the house and network is absolutely fine. When I disconnect from the WIFI and switch on Tailscale from the phone, it shows both ROCK and my iPhone connected. However Arc seems to be trying to connect and it said the server last seen two hours ago (but when I check Tailscale and Roon Remote after logging onto the home network again, it’s all fine). Any thoughts?

The only two thoughts I can guess could be an issue are:

1. On the Roon-settings-Arc element of Remote, the port forwarding keeps going back to 55002 even though I had previously entered 0.

2. One which may be a broader issue - when I updated ROCK, Roon Remote keeps wanting to find an old Core, as it’s now being classed as a new one. I did a backup restore earlier this evening to see if that would help, but just now on my MacBook, it said “searching for core” and I sometimes have to manually select the “new” one, even though it’s the same NUC.

Weirdly, if I’m connected to the WIFI with my phone, Roon Arc can’t connect.

[benjamin]

Hey @David_Flynn,

Thanks for the update!

I think there’s a broader issue at play with connection to your Roon Server - when you review your device list within your router settings, are all Roon devices within the same subnet?

I’d give your router a fresh reboot if you haven’t yet as well.

It may be worth testing out a different DNS server on the ROCK - we have seen users have a better experience in the past if they change their Router’s DNS servers from the ISP provided ones to Cloudflare DNS, Quad9 or Google DNS. Can you please give this a try and let me know if it helps?

If you still have issues after the above, try clearing your Roon Server cache:

• Exit out of Roon
• Stop RoonServer via the Web UI
• Find and open your Roon database
• Navigate to RoonServer/Cache
• Move the contents of the /Cache folder elsewhere, like your desktop
• Try restarting Roon and verify if the issue still occurs

Let me know if any of the above help!

[David_Flynn]

Hi Ben,

Thank you so much for your help and guidance! Just before I tried any of the options below, I essentially re-installed the Roon app on my devices (iPhone, iPad, MacBook) whilst also logging out of Tail Scale on WebUI, and logging in before rebooting. Since then it’s all worked perfectly.

Thanks again for your help and advice,

David

[connor]

Great to hear @David_Flynn. Thank you for the update. If you have any issues moving forward, please reach out in a new topic thread, as this post will soon auto-close.