Roon App Cannot Find Core on Nucleus One (ref#DK26BY)

Is Roon Server running?

· Yes, Roon Server is turned on and running.

What do you see on your screen?

· "Looking for your Roon Server"

Please try to restart your Roon Server by closing the Roon app in the taskbar or rebooting your Roon Server machine.

· No, the issue remains the same

Please try to restart your network setup by unplugging, waiting 30 seconds and then replugging in your networking gear.

· No, the issue remains the same

Please select how you've connected your Roon Server to the internet

· Roon Server is connected by *Ethernet*

Have you checked your firewall settings to ensure that Roon is allowed through?

· Roon still won't connect even after checking this aspect

Have you verified that Roon Server is on the same subnet as your Remotes?

· My Remotes and Server are on the same subnet and I still can't connect

Sometimes the issues can be resolved with a reinstall of your Roon Remote app. Let's try to perform a reinstall and see if it helps.

· I've reinstalled the Roon Remote but it did not help

What is the operating system of your Roon Server host machine?

· *Nucleus*

Select any of the following components that are present in your local network setup

· None of the above

Describe the issue

New Out-Of-Box Nucleus One: Roon App on MAC cannot find Core. Roon App on IOS cannot find Core

Describe your network setup

iMac Ethernet wired to Fortinet S224E switch. Nucleus wired to same switch and same VLAN/subnet. Naim MuSO Gen 2 wired to same switch, same VLAN/subnet. All three devices show link and data on the switch.

Did you try releasing and renewing your IP address? DHCP could not assign an iP address to my Nucleus One until I did that.

I changed ports for the Core, the Remote App on iMac, and the Naim Muso to put them on a different VLAN with, of course, different subnet, but all the same.

Then, I removed them from the Fortinet Switch, which is connected to and managed by the Fortigate Firewall, and connected all three to a dumb L2 switch connected to an Netgear ORBI, different subnet.

No change.

MacOS Firewall is turned off. The Fortinet Firewall is on implicit allow for outbound. On Ingress proxy filter, No blocking on anything with Roon or RAAT.

Flummoxed I am. Disappointed,

What happens if you click Configure Roon OS devices on your network?

I note that you have a managed switch and are using VLANs. Roon uses multicast to discover its devices. Are you sure that multicast is enabled in your network?

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Hi @Melissa_E_Davis,

Ben with support here - thanks for taking the time to write in, and congrats on your new Nucleus One!

I was able to pull your account up, and see the Nucleus was online and active recently, are you still running into issues here?

Let me know your status, thanks! :+1:

I am still having issues. Roon has been on and connected to Ethernet ports on switch, same VLAN and IP subnet as the iMac, iPhone, and Naim Muso which earlier it identified as a device end point.

MacOS Firewall is turned off, so allowing the roon servers are not the issue.

Earler in the week, it took some 11 hours for the connection. Today, after power off and unplugging, it has been on for 11.5 hours and still the Roon app, restarted several times, keeps searching for the Core.

Please help. I have had Roon since 2020, RevA. I love it, but these “non-happenings” are straining my faith in you.

[moderated: email address removed for privacy reasons]

Hi @Melissa_E_Davis,

Thanks for the follow up!

Using VLANs falls outside the scope of Roon support, are you able to temporarily disable your VLAN and set it up within your physical local network and test to see if the same issue occurs? Based on a recent Roon Server diagnostic report from your Nucleus, we’re seeing the following errors repeat:

Warn: [easyhttp] [1] POST check network configuration: socketerr (NetworkUnreachable): Network is unreachable
Warn: [easyhttp] [2] POST check network configuration: socketerr (NetworkUnreachable): Network is unreachable 
Warn: [easyhttp] [3] GET check network configuration: socketerr (NetworkUnreachable): Network is unreachable

I believe simplifying your overall network setup will likely lead to success in connecting. See if you’re able to get a direct ethernet connect to your router, bypassing all other network gear, and let me know how things go. :pray:

12 June 2024:13:41

Thanks for your guidance, Benjami. Your interest in this case is appreciated.

Current Status:

Nucleus One, iMac Pro, Naim Muso (Roon Ready Device and previously recognized) have been moved from the Fortinet kit with VLANs to the simplest of networks.

@ 0615 this morning: Netgear ORBI 960 directly connected to ISP. Nucleus One, iMac, Naim Muso plugged into the LAN ports on back of the ORBI. All are on the subnet, no VLANs. Nucleus turned off before plug in >30 sec.

Still no connection from either the app on the iMac Pro or mobile app on iPhone after 5 hours. Both remote apps show “Looking for your Roon Server”.

I am able to get gmail and browse the web from the iMacPro, and from it, play songs stored on the iMac on the Naim Muso. Hence, it appears that the network connectivity and DHCP are intact, even though I cannot see the Nucleus One.

I have several times turned off and unplugged the Nucleus One, leaving it off for < 30 sec to release the IP.

This is how things are going.

Please advise on any other options you can think of. I love Roon and have had my Nucleus Plus since 2020, but it seems to have died. I am in hopes that the Nucleus One can replace it.


Hey @Melissa_E_Davis,

Thanks for the detailed followup, and for the time with setting up the network conditions, I know it can be tedious and time consuming!

If you review the router settings, and the active list of devices with their IPs, do you see the Nucleus?

A next step in troubleshooting is to plug the Nucleus into a monitor via HDMI, all while connected to your router, and share a screenshot of what you see on the screen.

We’ll be on standby for your reply :+1:

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Morning here now. Just letting you know I am in process of complying with your instructions.

The ORBI, as a consumer grade device, does not show, or at least I do not know how to show, connected devices.

So, I am moving the Roon, the monitor, etc., to the basement for proximity to the Fortigate Firewall Router and creating on it a virtual hardware switch. This will allow me to eliminate the hypothesis of Double-NAT. The Virtual hardware switch will have only a single NAT at the Edge device. Thus devices that use NAT’s PAT will be connected as the Fortigate is my Edge Device, acting at L3/4 just as a ISP device to ONT.

The Fortigate GUI interface will allow me to meet the first of your instructions, as it will show connected devices on each port.

I will install the Roon App on either a Windows or Mac laptop to see if it can then connect.

ELSE: will connect the Nucleus One to the Monitor via HDMI to USB adapter. I do not have a HDMI or DP monitor. I will upload a screen shot to my eventual report back to you.

This should take a while to move and reconnect, so please be patient with me.

Problem is on my side with the Fortinet equipment: it being very security oriented, not tolerating any PAT, at least by any configuration options I can yet find.

I could see the Nucleus One and its MAC address on the Fortigate switch management GUI. There is no East-West traffic, but fine on North-South, which is why you could see it, but neither the iMac Pro nor the iPhone app on the same subnet could not Moving it to a Virtual Switch on the Fortigage Firewall/Router itself, the DHCP server would not give an address.

Now directly connected to the back LAN side of a consumer grade Netgear ORBI, with the iPhone on the same WiFi subnet, and the Muso streamer plugged into the same switch: music is happily playing.

Thank you for your patience.

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That’s excellent news, great work @Melissa_E_Davis! Happy to hear you’re able to get back to your music. :pray:

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