IPv4 Network Error and UPnP Action Failed during Connectivity Check (ref#ASKBYC)

Support
1

Network Setup

· Do you have a mesh network? (Google Mesh, Eeros, Ubiquiti, etc.)

ARC Status

· ARC is *Not Ready*

Roon Error Code

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

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

{
"ipv4_connectivity": {"status":"NetworkError","status_code":504,"error":"error code: 504"},
"external_ip": {"actual_external_ip":"149.aaa.bbb.fff","actual_external_ipv6":"null","router_external_ip":"null"},
"natpmp_autoconfig": {"status":"NotFound"},
"upnp_autoconfig": {"server_ip":"192.168.1.1","found_upnp":true,"error":"s:ClientUPnPError501ActionFailed"},
"multinat_autoconfig": {"status":"Failed","error":"Unknown Error code"}
}

Describe your network setup

Nether Orbi mesh router with 2 satellites. RoonServer running on a Windows 11 HP PC. ARC on iPhone 17 Pro Max running iOS 26.5

2

Hi @AlanC,

Thank you for your post.

This diagnostic indicates that your Roon Server has tried, and failed, to work together with your router’s UPnP stack to open the port. This might be because UPnP hasn’t been enabled, but it’s more commonly because either:

a) a second router is active on the same network or

b) your ISP has implemented CG-NAT

If you only have one Orbi router with no ISP-provided gateway, then this will likely be CG-NAT.

If you do have a second router, you can try:

  1. enabling UPnP in both routers

  2. if that doesn’t work, creating a manual port forwarding rule per these instructions:

  1. if none of this is working, your Windows 11 configuration will support Tailscale. This is a workaround to port forwarding that allows ARC to connect.

We’ll watch for your response. Thank you!

3

Hi Connor

Thanks for your reply. I have only one router, and I’ve implemented port forwarding without success. I’ll try Tailscale next.

A

4

Hi @AlanC,

If you only rely on a single router and still encounter double-NAT, it’s most likely the case that your internet provider has implemented their own CG-NAT above the level of your account.

Tailscale will work reliably if you’ve already configured that at this point. However, another last-resort option is to reach out to your ISP and inquire if they have dedicated external IPv4 addresses available for residential-tier accounts.

Let us know if this helps. Thank you!

5

Thanks Connor. I’ll ask my ISP about this before installing Tailscale.

6

You’re welcome @AlanC ,

We hope your ISP helps you with dedicated IP.

Fingers crossed!