iPhone app can't find Nucleus+ server post-troubleshooting (ref#15JD5V)

Support
1

What’s happening?

· I'm having trouble connecting to Roon

What type of connection issue?

· Something else

How can we help?

· None of the above

Other options

· Other

Describe the issue

The i-phone app that I downloaded onto my Apple i-phone can't find my Nucleus+ server after I have followed instructions on how to solve the problem.

Describe your network setup

ASUS GT-AC5300 router; Netgear GS316PP ethernet switch; Linksys SE2008 ethernet switch

2

Are you sure they are all on the same Internet subnet?
Example 192.168.12.xxx?

3

The IP addresses for both start with 192.
The Net mask for both is 255.255.255.0

4

It’s the first three groups of numbers in an IP address that need to be the same to prove that different devices are in the same subnet, not just the first group.

5

Hey @Greg_Johnson !

Are you able to connect to web ui of your nucleus from the phone sitting on the same network (

) ?

If so, please try to enter the IP of server manually as on screenshots attached.

Regards!

6

They are the same. Both of them have the following IP address 192.168.50…

7

Hey @Greg_Johnson !

Okay, thanks, but can you access the web UI of nucleus ?

This will help us to narrow down the scope of the issue.

Thanks!

8

Yes I believe that I can if I am understanding you correctly.

9

Got it, thanks @Greg_Johnson!

Let’s temporarily bypass your network gear, and see if you’re able to connect with the Nucleus hardwired directly to your primary router.

We’ll be monitoring for your reply and results - thank you! :folded_hands:

10

Sorry to take so long to respond. My Nucleus+ server was and still is directly connected to my ASUS GT-AC5300 router. Inspite of that the problem still persists.

11

Thanks for the update @Greg_Johnson - it does look like there’s a potential that your iPhone could potentially be jumping across a few different subnets within your network.

If possible, could you temporarily test out disabling all but a single subnet, then reboot your router and devices, and see if the behavior changes?

Thank you! :folded_hands:

12

i disabled all but the single subnet for my Nucleus+ & rebooted my devices. The Roon app behaviour did not change.

13

Hello @Greg_Johnson,

Thank you for the update.

We’ve reviewed the diagnostic data from your Nucleus+, and everything looks normal on the server side. The unit is receiving a valid IP address from your router and is fully reachable on the network. This strongly suggests that the issue is occurring on the iPhone side, not the Nucleus.

To move forward, please double-check the following on your iPhone:

1. Roon app has permission for Local Network Access

Go to:
Settings → Privacy & Security → Local Network → Roon → Enable

If this toggle is off, the app cannot discover any Roon server.

2. No security apps or blockers are interfering

Please ensure you do not have:

  • VPNs (NordVPN, ExpressVPN, iCloud Private Relay, etc.)
  • Ad blockers (AdGuard, Lockdown, etc.)
  • Security filters (DNS filters, Pi-hole profiles, custom DNS profiles)

Any of these can block Roon’s discovery protocol.

3. iPhone is on the same Wi-Fi network as the Nucleus

Some ASUS routers create multiple Wi-Fi segments (Guest, AiMesh, etc.). Make sure the phone is on the primary SSID and that “AP Isolation” or “Client Isolation” is disabled.

Once you verify the above, please restart the iPhone and try to connect again.

Let us know the results — we’ll continue from there.

14

I checked the items on my iPhone that you asked me to, to the best of my ability, and re-booted my iPhone - a brand new iPhone 17 Pro Max that I got on Monday and still the Roon app on my iPhone cannot find my Roon server.

15

Hey @Greg_Johnson !

What happens if you manually enter the IP of the nucleus in the Roon app?

Does it pair?

Regards.

16

I’ve tried that before but I tried it again just a few minutes ago. It does not pair.

17

Hi @Greg_Johnson,

My apologies if this has been glazed over - could you try:

On the iPhone:

Settings>Apps>Roon>Toggle the Local Network

Try again - if no luck, head back to this settings page and toggle on ‘Reset Roon Remote on next startup’ and see if that helps.

Thank you!

18

I followed your instructions regarding toggling on the Local Network. I had previously done the same. Whether the Local Network is toggled on on or off makes no difference. The Roon app on my iPhone can’t find my Roon server.

I also previously clicked on “Reset Roon Remote on the next startup” Again that did not correct the problem.

19

Hello @Greg_Johnson ,

Looking over diagnostics, I noticed that your iPhone was recently using a
http://192.0.0.XYZ
&
http://10.0.0.XYZ
range instead of the 192.168.50.XYZ that you mention. In some routers, it can be configured that the WiFi and Ethernet subnet ranges are different. Is this perhaps what is happening on your end?

20

My router app shows that the IP address for my iPhone is 192.168.50… I don’t understand why diagnostics showed it using different IP addresses.