ARC Timeouts with Port Forwarding

The error also appears on my Core (Mac Mini), but ARC on the iphone still works

Hi @Frank_Remmert,

ARC will connect without issue to your Core as long as your phone and Core are on the same Wi-Fi network - even if port forwarding has not been configured yet.

If you’re seeing a diagnostics message similar to the users above, please paste it here (be sure to hide fields listing your external IP address). The team will be happy to begin the troubleshooting process and break your message into a new topic thread as necessary.

Please note that a multiple NAT-layer situation is the most common snag users encounter when first setting up port forwarding. You can read more details about this problem and how to resolve it on your network in our Help Center article here: .

The team will be watching for your response.

Thank you Connor.
My diagnostics data:
“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”: {“server_ip”:“”,“found_upnp”:true,“error”:“<?xml version=\"1.0\"?>\n <s:Envelope xmlns:s="\” s:encodingStyle="\“>\n<s:Body>\n<s:Fault>\ns:Client\nUPnPError\n\n<UPnPError xmlns="urn:schemas-upnp-org:control-1-0">\n403\nNot available Action\n\n\n</s:Fault>\n</s:Body>\n</s:Envelope>”}

Hi @Frank_Remmert,

Thank you for reaching out for assistance with port forwarding. I’ve split your post into a separate thread so the team and other users can assist you more directly.

Can you provide the following details about your network setup to help expedite troubleshooting?

  1. Who is your internet service provider?

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

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

  4. Does your network have any VPNs, proxy servers, or enterprise-grade security?

  5. What machine are you using as a Roon Core, and how is it connected to the internet?


Hi Connor,
my internet service provider here in germany is
My router is the Fritz!Box 7490 Fritz!OS 7.29
I use some Powerline Repeater and WLAN Repeater
VPN, proxy servers…puh, I have no Idea. enterprise-grade security: no.
As a roon core I’m using the Mac mini late 2012, works fine. Firewall is off.
The Mac Mini also runs homebridge, could that cause problems?