Android can't find Roon Core

Well, here it is February 2020 and I’ve just had my LG 40 phone (Android 9) “fail to find the core”. Putting in the correct IP address did not work but the workaround above did. This is a new install of Roon (I’m still in the 14 day trial period) so all components are freshly downloaded. So it seems not much progress in resolving this Android problem.

The notes on the thread state that there is more than likely an underlying network issue with multicast traffic causing the error. No application fix would work here.

it worked!!!

Im having this issue also. i bought a FireHD 10 tablet just for ROON remote i have done all the ROON troublshooting with my router Enabled multicasting exc even my Android phone wont connect it finds the Core ok but just says failed to connect

Have you tried the workaround?

No not tried that how do you do the work around

The link I shared tells you what to do, I don’t know anything more than that.

On my side:
Tried with Dlink switch then TP Link TL-SG105E / TL-SG108E with/without IGMP proxy.
Wifi Mesh Deco M5
Running in Docker with Debian base image.

As soon as it is not working restarting the server allow me to connect on Android but always with some delay compared to iPhone…
iOS using the same WIFI without issue.
I dont see how a network issue can have impact only iOS…
As I’m on trial I dont know if i will keep using it with that issue. Too bad as I’m happy with it but seeing that issue for so long on the community is not engaging.

like every morning my Android devices does not work. I need to disconnect and then use the trick with broadcast IP address (255.255.255.255) which works or restart the server.

Your router is IGMP ready ?

@ComasSky no router involved Deco M5 directly connected to the switches.

Android <-> WIFI (Deco M5) <-> Switch (TPLink 108E) <-> Switch (TPLink105E) <-> Server
All on the same network.
I’ve tried with and without IGMP proxy on the switches but it does not solve the issue.
Deco M5 are in AP mode

For my morning problem it seems to be related to inotify.
After trying to tail log file i’ve seen that there is no more inotify watche.
I’ve bumped in /etc/sysctl.conf with:
fs.inotify.max_user_watches=1048576
No more issue so far except that Android take more time to connect.

Hi Terry,

A message from the future. The world is succumbing to a terrible virus and we still don’t have flying cars.

Also, this problem with Roon and Android still exists.

On the plus side, your advice about 255.255.255.255 still works.

So thanks!

In return, I’d urge you to stockpile toilet paper now before the great Andrex rush of 2020.

Regards,
Mark.

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Hi Noris,

Worked for me. None of the Android devices in my house have been working for the last month or so. It may be coincident with a change in firewall / DHCP host to pfSense. Having said that, it was intermittent before that.

Wifi - Netgear WNDAP660
Switch Netgear GS724TP

Windows 10 Pro for Roon Core

Android on LG G7 Thinq, Moto G7, Moto G8 Power, Nexus 7

Roon core v1.7 b528

Windows clients have been rock solid, the issue has just been on Android.

Cheers,
Mark.

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I have an Asus RT-AC3100 with the most recent firmware. Mesh network connects Asus RT-AC3100 and Asus RT-AC68U. NUC with Roon OS hard wired to Asus RT-AC68U. IGMP Snooping, IGMP Proxy enabled. On router. I have an iPad, a Pixel 3 and a MacBook Air. The iPad and MacBook air connect flawlessly. The pixel 3 with all the most recent software requires the 255.255… work around. And takes longer to connect every time. I keep hearing this is a multicast issue but I find it really hard to believe given the fact that all my other hardware works flawlessly. I would be more inclined to believe it is an Android roon software issue. It is really frustrating that this is still a problem. It has not resolved with multiple software updates. I have the exact same problem. Can’t find the core even if I put the IP. Even when I make the IP static on the core. The only way to connect is to use the 255.255… workaround. This is most annoying because it takes longer to connect the Android devices every time the app is opened. Can someone at roon just buy an Android device and repeat the problem so you can see how frustrating this can be so us Android users can have software that works as advertised. Thank you.

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They have multiple Android devices. It works for me all the time even on my crappy old android phone that sits in the garage.
I’ve had Oneplus, Huawei, Google, Samsung and LG Android as well as a pioneer Android DAP and all work.
A couple of years ago it wasn’t guaranteed but on current builds connect first time every time.

I have no problems with my Pixel 3 on mesh WiFi either. Roon is incredibly network sensitive, hit the sweet spot and life is wonderful, anything slightly off and Roon spits the dummy out.

They have plenty of Android devices. I even gave Roon access to my home network to try to debug Android issues a few years ago. They observed the problem on my home network, took network traffic dumps, but they could not replicate it in their lab. Then I tweaked my home network by turning off IGMP snooping on a managed Netgear switch, and the problem disappeared. No Android issues since, even though I changed much of my network gear when I moved last year. I’m convinced that there is a subtle interaction between the Android network stack and some network switches (or routers), maybe around some slight disagreement on one of the fine points of multicast or IGMP.

I don’t know whether it’s just because it is popular, but Asus seems to come up quite often in Roon networking problem reports. Except for that Netgear managed switch, my Ubiquiti network hardware and Netgear dumb switches have been flawless. Ubiquiti’s AmpliFi consumer WiFi mesh is great, too. I have a somewhat complicated home network: Ubiquiti EdgeRouter with load-balancing dual WAN, Actiontec MoCA transceivers for internal network wiring on coax (no easy way to run cat 6 through concrete, coax was already there), AmpliFi WiFi AP and mesh points, Netgear switches, Synology NAS, Ubuntu NUC core, Pi-based streamer, two Linn systems, several other devices. Pixel Android and iPad Roon control points. It all just works.

I am having the same issue with Android 9 on LG G7 connect to a windows 10 roon server over a netgear ORBI network.

I would agree with the statement that it should be easy for Roon to update their Android App to force 255.255.255.255 automatically when it has delays connecting to core. It is pretty annoying to expect users to do this over and over and over …

I’ve never understood why Roon didn’t just use mDNS for local LAN discovery of the Core and endpoints. So much more reliable, and taken care of by the OS.