Attention Salt. Users in Switzerland: CG-NAT Blocks Port Forwarding, Workarounds Required (See Staff Post)

done, I still get the following reply:

“connectivity”: {“status”:“NetworkError”,“status_code”:504,“error”:“error: Error: ETIMEDOUT, response code: undefined, body: undefined connected? undefined”},
“external_ip”: {“actual_external_ip”:“”,“router_external_ip”:null},
“natpmp_autoconfig”: {“status”:“NotFound”},
“upnp_autoconfig”: {“status”:“NotFound”}

Thanks for helping, Stefan … I’m a bit lost here, but I can imagine, others will be too.

FYI. Roon ARC only uses TCP. Including UDP won’t make any difference whatsoever.

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Try to reboot the salt-box

Funny how ARC works with my Salt box even without port forwarding. Problem, it only works for about 15 minutes and then I can’t connect anymore if I don’t restart roon and the arc app.

had no effect, unfortunately

Check, if the firewall has created such a rule (sorry, I’m not familiar with Salt HW/SW) and don’t know if they make this transparent to the user. If not, I’m nvolve the Salt call center

Salt is IPv6 oriented. I had a Salt Fiber when I was an expat in Basel for 4 years.
I received a private IPv4 address (10.12.x.x) on the public interface of the router. If that’s still the case , it will never work. There are two solutions I can think of: either you pay approx 10 CHF/month to Salt for a publicly accessible IPv4, or you define an IPv6 VPN solution that translates to IPV4 on the core and client.

What port is configured in Roon Settings → Roon ARC? The ports need to match exactly. And the IP you enter here needs to be your Core IP, which may change if you did not do an Address Reservation on it.

Also, the protocol should be TCP.

I changed it to TCP and added the information from the Roon > ARC Settings page. Although I’m not sure, what value I should enter really for each of the two port entries … 4 x the same number?

However, it still does not work

I checked again with customer support from Salt, and I got the following reply:

So - it really seems not to be supported with the current version of Salt box

I then asked about the publicly accessible IPv4 or VPN solution @Georgethesixth mentioned and he recommended to book an IPv4 … but I’m not sure if I want to pay another 10.- monthly just to use ARC. Also there’s no guarantee that it will work …

it seems at the moment, this is the way to go for Salt customers:

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Hi everyone,

Unfortunately, as @Tobias_Imbach and several other users have already realized, 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. Note that the team is actively researching workarounds to IPv4 port forwarding that will potentially allow for our users dead-ended with CG-NAT to access ARC on-the-go as designed. However, we don’t have a timeline or a guarantee of success for these potential future Roon-supported workarounds.

To summarize, there are three current workarounds Salt. users can take to access ARC, although they do fall within the realm of our #tinkering solutions:

1). Contact Salt. support to request a static IPv4 WAN IP address for a monthly fee. Note that, depending on the age of your Salt account, you may be able to grandfather into a static IPv4 if you originally had one reserved.

  1. You can try out TailScale, a workaround explored in our #roon and #tinkering section (see above)

  2. You can try out various third-party VPNs, as discussed here, for example.

Thank you for your patience, and we’ll post here if we find any additional helpful information.

Roon Core Machine

Apple MacBook 1.3 ghz dual core i5 8 gb

Networking Gear & Setup Details

Salt router Switzerland on wifi no vpn

Connected Audio Devices

naim uniti

Number of Tracks in Library

6000 tracks

Description of Issue

How can i install Arc with a Salt router? Get error messages.

error message:
“connectivity”: {“status”:“NetworkError”,“status_code”:504,“error”:“error: Error: ETIMEDOUT, response code: undefined, body: undefined connected? undefined”},
“external_ip”: {“actual_external_ip”:“”,“router_external_ip”:null},
“natpmp_autoconfig”: {“status”:“NotFound”},
“upnp_autoconfig”: {“status”:“NotFound”}

If I remember well from my time in Switzerland, you have a problem with the default Salt offering. Roon doesn’t support IPv6, as far as I know, and Salt shares one public IPv4 over different customers. You will only get ARC to work if you order a publicly accessible IPv4 address. I have never seen this config anywhere in Europe on a fixed line before. Most providers issue a temporary IPv4 that is publicly accessible. Then again, Salt offers a 10 Gbit connection with for the same price as I pay for a 500 Mbit down, 100 Mbit up so you are lucky. :slight_smile:

same issue here:

Hi @Lars_Sven_Willumeit,

I’ve merged your post into the existing thread for Salt users who are unfortunately up against their carrier-grade network address translation. Note that Roon is actively exploring alternative solutions, but we don’t have a timeline at this time.

Please see the staff post above here.

Any update on this? I have also the SALT box, can’t use Roon ARC; it’s frustrating :frowning:

It’s very odd as Plex connects perfectly all the time remotely, for my same library of around 300k tracks. Only issue is Plex is not bit-perfect. I didn’t even have to mod my router to get the Plex to work.

As an aside is there any chance the normal Roon Android app could be tinkered with to allow Bit Perfect? This would be a great start, at least to have Roon around the house bit-perfect via Android.

I switched/upgraded NUC and iPhone in the meantime and I can’t find the energy to make it work again via Tailscale. I won’t even try …

ARC with IPv6 support is currently in earlyaccess testing


Hi @Sallah_48,

Per @Suedkiez’s post above, the team is actively testing an implementation of ARC that works with many IPv6 accounts. For many users stranded by CG-NAT, this will allow ARC to function out of the box. We continue to make progress, although certain ISPs have more particular implementations that will require further work.

If you’re interested in joining the testing pool, please see our Knowledge Base article on the #early-access program and feel free to reach back out here.

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