· I've got a fiber internet connection, my internet provider is Odido (NL). The connection is made with a fiber modem, Zyxel EX5601-T1. Via UTP cabels are two routers connected: Netgear GS108Ev3 and TP-Link TL-SG108E. I'm running Roon Rock Serial #94C69119F02D version 1.0 with Roon Server 2.67 (build 1661). After the Roon ARC test I get this diagnostic info: { "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":"62.aaa.bbb.ccc","actual_external_ipv6":"2001:ddd:eee:fff:ggg:hhh:iii:jjj","router_external_ip":"null"}, "natpmp_autoconfig": {"status":"NotFound"}, "upnp_autoconfig": {"server_ip":"192.168.178.254","found_upnp":true,"error":"
s:Client UPnPError
501 Action Failed
"}, "multinat_autoconfig": {"status":"Failed","error":"Unexpected uPnP Control Response - See Log"} }
Odido isn’t among the providers in the Netherlands known to have implemented CG-NAT across accounts, so there’s a good chance we can resolve this in your router and Roon settings without having to reach out to your ISP.
You’ll need to bypass the double-NAT created by having a second router active in this setup. One option is to ensure UPnP is enabled in both rotuers; more recent versions of Roon can daisy-chain autoconfiguration between two routers, but this is failing in your case.
Another option is to place one of these two routers in Bridge-mode or modem-only mode.
The third and most reliable option is to create an identical manual port forwarding rule in each of your two routers’ admin settings pages. This is usually under the Firewall or NAT section, but we can assist with these particular routers if you’re having trouble. The port forwarding rules must be TCP-format and match the port number and IP address in your Roon Settings page.
Thank you for your reply. But I’m not aware I have two routers in my network. I have one Zyxel EX5601-T1 router and two switches, not another router. So i do not know how the port forwarding.
You are absolutely right, and I apologize for the confusion! I double-checked those model numbers, and the Netgear and TP-Link devices are indeed network switches, not routers. There is no double-NAT happening on your network.
Looking closely at your diagnostic error message, we can see exactly what is causing the block: "upnp_autoconfig": {"server_ip":"192.168.178.254","found_upnp":true,"error":"UPnPError 501 Action Failed"}
This means Roon successfully found your Zyxel router (192.168.178.254) and asked it to open a port automatically using UPnP, but the router’s software rejected the request (Error 501). This is very common, as the UPnP implementation on many ISP-provided routers can be quite buggy.
To fix this, we just need to bypass UPnP entirely and set up a Manual Port Forwarding rule directly in your Zyxel router.
Here are the steps to do that:
1. Gather Your Roon Details
Open Roon and navigate to Settings > Roon ARC. Write down the exact Port number and the IP Address listed there for your Roon Server.
2. Log into the Zyxel Router
Open a web browser on your computer and type in your router’s IP address: 192.168.178.254. Log in using the admin credentials (usually found on a sticker on the back of the modem).
3. Create the Manual Rule
Navigate to the Network Setting menu, then select NAT or Port Forwarding.
Add a new rule with the following parameters:
Protocol: TCP
WAN / External Port: Enter the ARC Port number from step 1.
LAN / Internal Port: Enter the ARC Port number from step 1.
Server / Internal IP Address: Enter the Roon Server IP address from step 1.
Save or apply the rule.
4. Restart and Test
Once the rule is saved, restart your Zyxel router. After your network comes back online, open Roon > Settings > Roon ARC and test the connection again.
Please drop a reply here if you have any trouble finding the NAT settings inside the Zyxel admin page.
One more thing to check - could you compare the WAN IP address shown in your Zyxel router’s status page with the IP address shown on
?
If they are different, your ISP is using CGNAT (carrier-grade NAT), which would prevent ARC from working regardless of your port forwarding setup. Let us know what you find!
I’d bypass all other network gear temporarily, and get a direct ethernet connection from your server to your primary router, reboot everything, and let me know if you’re able to connect.
After you made your manual port forwarding rule, did you also disable UPnP? That might be worth testing as well.
