ARC Port forwarding issue (ASUS router)

Same problem here:

“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”:“”},
“status”: “status”: MultipleNatFound
“natpmp_autoconfig”: {“status”:“NotFound”},
“upnp_autoconfig”: {“server_ip”:“”,“found_upnp”:true}

Here’s a snapshot of the Roon ARC configuration screen:

I have an Asus ZenWifFi AX router configured to enable port forwarding.

I also have a BT Home Hub 5 to connect to the Internet, again configured with port forwarding:

Would love to get this sorted.

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Only enable TCP for the port forward, ARC doesn’t use UDP.

Personally I would never enable auto UPNP, create the port forward manually

Same problem here…
BE Telenet provider modem > ASUS RT-AC88U router > Synology NAS
UPNP and NAT active on router

still getting underneith error message
thanks for a resolution to this

{“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”: {“server_ip”:“”,“found_natpmp”:true},
“upnp_autoconfig”: {“server_ip”:“”,“found_upnp”:true,“error”:“<s:Envelope xmlns:s="\” s:encodingStyle="\“><s:Body><s:Fault>s:ClientUPnPError<UPnPError xmlns="urn:schemas-upnp-org:control-1-0">718ConflictInMappingEntry</s:Fault></s:Body></s:Envelope>”}

Change your NAT type to “full cone”

Asus gt-ax11000 - same issue

@Philip_Gibson I have a Plusnet Hub one router and it’s config screen is the same as yours. After much head scratching I’ve managed to sort it so I think it will work for you too.

Once you’ve created your ‘Game/Application’ with 55002, you then need to go a step further:

Go back to Port Forwarding and select the ‘Roon Game/Application’ from the first drop down. Then in the second drop down scroll all the way to the bottom and there is the option for ‘User defined IP address’, click that and then input whatever the IP is from your Roon ARC page.

Hit apply, and then go back to the Roon ARC page and refresh - for me it immediately said it was Ready. I downloaded the ARC app and all is working as advertised.

Good luck!

Images provided for each stage.





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Thanks for your fast reply and hint…
However, i am in firmware version 48260, no NAT type in there apparently

weird, according to asus it was added from 386_41700 onwards.

I’m running Asuswrt-Merlin on mine (ax86u)

[Wireless Router] How to change NAT type on ASUS Router? | Official Support | ASUS Global.

Thanks for your suggestion, @Bob_Scratchit. I’ve followed your suggestion:

Unfortunately, I’m still getting the same error message.

Thanks for your suggestion, @Red_R. I’ve followed the steps you’ve outlined and I’m still getting the same error message. I’ve also changed the settings on my Asus router, as per @Bob_Scratchit’s suggestion. Frustrating!

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I had to add a port forwarding rule in my ISP’s Fibre modem besides my router to get ARC to work.
Forwarded the port (52000 in my case) to my router IP ( in my case).

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To isolate the problem it would be useful to contact your ISP to find out if you are getting a public ip or a cgnat address.
Cgnat does not allow port forwarding which Roon ARC needs to work. In this case you may be able to get a real IPv4 address from your ISP.

Likewise, no 2 routers with activated NAT should be connected in series in your network. The first router should be in bridge mode or add a port forwarding rule to the second router to avoid a double NAT layer, since ARC port forwarding does not work with it.

Carrier-grade NAT usually prevents the ISP customers from using port forwarding, because the network address translation (NAT) is usually implemented by mapping ports of the NAT devices in the network to other ports in the external interface. This is done so the router will be able to map the responses to the correct device; in carrier-grade NAT networks, even though the router at the consumer end might be configured for port forwarding, the “master router” of the ISP, which runs the CGN, will block this port forwarding because the actual port would not be the port configured by the consumer.

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So, spent half an hour on phone to Internet provider and had a static IP address assigned - ARC recognised the Core immediately!

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CGNAT shouldn’t have any impact on local port WAN>LAN forwarding.

Thanks, @Axel_Lesch. I’ve just had a chat with my ISP, BT, and they’ve said that they provide Public IP address to all their residential customers (of whom I am one).

WRT the two routers, both the BT Hub and the Asus ZenWiFi have DHCP servers enabled. Should I disable the DHCP server on the BT Hub (all the wifi is dealt with via the ZenWifi)?


Here’s a guide how to set it up in bridge mode:

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Thanks yet again, @Axel_Lesch. Unfortunately, I have a BT Home Hub 5. It looks like it’s not possible to put it into bridge mode.

Too bad, mate!

If you’re feeling brave you can remove the BT home hub completely.

I’ve got BT FTTP and it uses PPPoE so I don’t use the hub and just have the ethernet plugged directly into my router.

The PPPoE for all BT home connections are:

Password BT