ARC MultipleNAT Suddenly When Port Forwarding Previously Worked (Sweden, Tele2)

Roon Core Machine

NUC Kit i7-10710U. Roons operating system.

Networking Gear & Setup Details

A switch Neatgear GS108T

  1. Who is your internet service provider?
    Tele2 (in Sweden)

  2. Please list the make and model of your modem and router?
    Com Hem Wi-Fi Hub C1 (Manufactured by Sagemcom for Com Hem Model F@ST 3686 V3 CH)

  3. Do you have any additional network hardware, like additional routers or managed switches?
    A switch Neatgear GS108T

  4. Does your network have any VPNs, proxy servers, or enterprise-grade security?
    No.

Connected Audio Devices

Linn Akurate DSM. Several smartphones, ipads, computers etc.

Description of Issue -

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

Have been running Roon as well as Roon ARC for several months now without any problems. Now suddenly ARC cannot connect with Roon Core when trying to reach it from outside (no problem for ARC to connect by wifi). Have tried the resetnetwork command on the Roon core. Have rebooted most HW. Have not made any changes in the fixed IP-adress and port that I previously (nov 22) entered in the administrator interface for the router. In Roon under “settings” and “Roon ARC” i get the message “Roon ARC was unable to securely access your ROON Core” followed by the following message:
{

“connectivity”: {“status”:“NetworkError”,“status_code”:502,“error”:“error: Error: connect EHOSTUNREACH 83.aaa.bbb.ccc:55002, response code: undefined, body: undefined”},

“external_ip”: {“actual_external_ip”:“83.aaa.bbb.ccc”,“actual_external_ipv6”:“null”,“router_external_ip”:“192.168.0.2”},

“status”: “status”: MultipleNatFound

,

“natpmp_autoconfig”: {“status”:“NotFound”},

“upnp_autoconfig”: {“server_ip”:“192.168.86.1”,“found_upnp”:true}

}

I really hope someone can help me…

Hi Mats,

The diagnostics you’ve provided suggest there is a redundant layer of network address translation preventing port forwarding. I would start by contacting Tele2 and see if you have CGNAT service.

This can either be at the local-network level (commonly as a result of two routers), or at the level of your service provider (in the form of carrier-grade NAT).

If your setup involves an ISP-provided gateway (modem/router combination) and your own third-party router:

  • In the web administration interface of the ISP-provided gateway (modem/router combination), enable Bridge Mode or equivalent, where the ISP-provided gateway does not have DHCP routing enabled.

  • Alternatively, if you have already created a manual port forwarding rule in your 3rd party router, you can add an additional rule to forward the port through the ISP/second router.

If you only have one router in your setup or your modem is already in Bridge mode, please take a look through our list of known router and internet service provider solutions, as other users may have already encountered the same situation: ISPs and Routers: List of Known Solutions and Workarounds

You can reach out directly to your service provider to ask if they support port forwarding; this question will often enough to prompt them to explain whether or not the carrier-grade NAT they’ve implemented can function with ARC.

More specifically, you can pass along the following questions:

  • Have you implemented carrier-grade NAT for my account level?
  • Have you fully implemented IPv6, or do you have IPv4 addresses available?
  • Can I request a static IPv4 address to support port forwarding?
  • Are there any ports you have reserved at the ISP level I should be aware of?

If you’re unable to locate an existing solution in our #support:port-forwarding-resources subcategory, please reach out to the Roon support team and include the following information:

  1. What is the make and model of your modem and router?
  2. Do you have any additional network hardware, like additional routers or managed switches?
  3. Who is your internet service provider and what is your geographic region?
  4. Is your Modem configured in Bridge Mode so that it operates only as a modem or do you have the ports forwarded on both?
3 Likes

Thank you Daniel, I will have a look into this. (Note that everything have worked just fine for many months. I have no idea what has happened sometime during the last few days or so, I have not manually changed a thing in the network. Hard also to track back exaktly what day Roon ARC lost it’s connection with Roon Core - I have not listened to music a lot via ARC for maybe a week or so now.)

It’s not impossible that your ISP changed how they do things and switched to CG-NAT. If your contract doesn’t guarantee you a proper public IPv4 address (most residential contracts don’t), they might not notify you about this.

1 Like

Hi @Mats_G,

I’m sorry to hear that you’ve suddenly lost port forwarding. The inclusion of the MultipleNatfound line does confirm there’s additional network address translation in the current setup, scrambling your Core’s upstream connection.

When this diagnostic messages appears in Roon → Settings → ARC after you’d already successfully configured ARC, one of two culprits is usually responsbile:

  1. As @Suedkiez mentioned, the ISP may have reallocated your external IP address and placed you behind carrier-grade NAT. After doing a little digging, it does appear Tele2 (as with Telia, Telia Öppen Fiber, Ljusnet, and a few others) is in the process of rolling out CG-NAT across their residential-tier accounts. It’s worth reaching out to inquire if a dedicated external IP address is available for your account (often, this will be offered as a static IPv4 address) and if you can grandfather into this option per your contract. Unfortunately, Tele2 does appear to charge more if the option to grandfather your previous static IP is not available.

  2. The second possibility is that a firmware update on one of the routers in your setup changed a setting. If you have a second router in your setup in addition to the Com Hem unit, I recommend placing that hub in Bridge mode: Brygga ComHem Wifi Hub C1 - Nätverk och uppkoppling

The first possibility is sadly far more likely than the second, based on our experience in the #support:port-forwarding-help section and testing ARC. Please keep us posted once you’ve had a chance to look through your setup, and we will be here to support you.

2 Likes

Thank you Connor for very thourough and informative input! Thanks also to you Suedkiez! I will look into this the upcoming days and report back ASAP!

Hey @Mats_G

1 Like

Thank you Ivan, I hope the team will find a solution soon! :blush:

No progress with this from the team?

Not sure if the link by @Axel_Lesch was related to your issue. This was about the ARC app not connecting, but there was no error in the Roon settings like you have, see the screenshots in the first post of that link. Plus, this was resolved:

I’m afraid it’s probably still one of the things Connor mentioned

1 Like

Thanks Suedkiez for input. I guess I have to act on this ASAP, right now I am sick and have no energy for stuff like this, just would like Roon ARC to be little more of a plug-and-play app from this my personal context… Will use Qobuz own app instead listening when not at home.

1 Like

Get well soon!

They are working on an IPv6 solution,

Have finally had some time today to try to get this to work, however with no success. I conclude that Roon ARC is not for me - much to technically complicated for me to get this to work. Port forwarding does not seem to be possible with my router (now a C2 model from Tele2) as it is now. :cry: