Have you successfully located and enabled the UPnP or NAT-PMP settings in your router's web UI?
· I've turned UPnP/ NAT-PMP on and ARC won't connect
Select the Diagnostic Keyword or Text String
· Something else
Don't give up yet.
· I'm stuck. I'd like to create a post to ask Roon Community for help.
Describe the issue
I've recently upgraded to an Eero Pro 7 network mesh, and now the arc doesn't work. Wondering if anyone has got a work around Error I see. { "ipv6_connectivity": {"status":"NetworkError","status_code":504,"error":"error code: 504 "}, "ipv4_connectivity": {"status":"NetworkError","status_code":504,"error":"error code: 504 "}, "external_ip": {"actual_external_ip":"118.aaa.bbb.ccc","actual_external_ipv6":"2404:ddd:eee:fff:ggg:hhh:iii:jjj","router_external_ip":"100.kkk.lll.mmm"}, "status": "status": MultipleNatFound , "natpmp_autoconfig": {"status":"NotFound"}, "upnp_autoconfig": {"status":"NotFound"}, "multinat_autoconfig": {"status":"Success","error":"No Error","routers":1,"routers_mapped":1} }
It looks like your ISP is providing your service using CG-NAT.
This being the case, you have two options:
Change you ISP service either by getting your broadband from a different company or getting the current company to issue you with a public IP address that supports port forwarding (usually at extra cost).
Use Tailscale to avoid then need to set up port forwarding.
The Roon setup guides for Tailscale can be found on the pages linked from
Unfortunately, this guide is not complete because it does not address the Nucleus and Nucleus Plus devices (or ROCK installs using BIOS boot) - only the Nucleus One and the Nucleus Titan and more modern Rock installs using UEFI boot.
For those devices running BIOS boot RoonOS (Nucleus, Nucleus Plus and older ROCk installs), you will have to install Tailscale on another computer (which has to be left turned on whilst you wish to have ARC connectivity - hence low power consumption devices like the Raspberry Pi are popular) and configure Tailscale as a subnet router. Instructions for doing this can be found at:
Thank you for reaching out and providing such detailed diagnostic information! I’d also like to give a big thank you to @Wade_Oram for jumping in - his assessment is absolutely correct.
The diagnostic code you shared explicitly shows the "status": "MultipleNatFound" error, and your router’s external IP address (100.kkk.lll.mmm) falls perfectly into the standard IP block used for Carrier-Grade NAT (CG-NAT).
CG-NAT means your Internet Service Provider (2 degrees NZ) is sharing a single public IP address among multiple households. Because you do not have a dedicated public IP, the port forwarding protocols that Roon ARC relies on (UPnP/NAT-PMP) cannot successfully route external traffic through your Eero mesh network and back to your Nucleus.
To get ARC up and running, you have two primary options:
1. Contact your ISP (Recommended) This is usually the most straightforward solution. Reach out to 2 degrees NZ and ask if you can opt-out of CG-NAT or request a “dedicated” or “static” public IP address.
What to say: Let them know you are trying to set up a home server that requires port forwarding.
Note: Many ISPs will make this change for free, though some may charge a small monthly fee for a static IP. Once you have a dedicated public IP, your Eero’s UPnP settings should instantly allow ARC to connect.
2. Use Tailscale (No Port Forwarding Required) If your ISP cannot provide a public IP or charges too much for one, you can use Tailscale. Tailscale creates a secure, private network that entirely bypasses the need for port forwarding.
Important Note for Nucleus: Because you are using a standard Nucleus (which runs on a legacy BIOS version of RoonOS), Tailscale cannot be installed directly onto the Roon Server itself.
The Workaround: You will need to install Tailscale on another device on your network that is always turned on (like an always-on PC, Mac, or a low-power device like a Raspberry Pi) and configure that device as a Subnet Router.
You can read more about setting up a subnet router in Tailscale’s official documentation here.
Getting off CG-NAT via your ISP is highly recommended as the most seamless path forward, but Tailscale remains an excellent fallback.
Just checking in on this and wanted to see whether you had a chance to ask 2 degrees NZ about opting out of CG-NAT or getting a dedicated or static public IP. If that is not an option, were you able to try the Tailscale workaround we mentioned, with Tailscale running on an always-on device set up as a subnet router? Let us know what you found out, thanks.
We have not heard back from you, so we will go ahead and close this thread due to inactivity. If you need further assistance, please submit a reopen support request via the technical support help form link and specify that the issue be reopened. Thank you.