RUTX50: recurring fail of connection without reconnecting

Hi there,

I am running a RUTX50 with one SIM card. Last year I had no mobile conncetion issues.
I did not use the router over winter time, when I re-activated it in April first I did was updating firmware (also for modem). Since then, I have massive mobile connection issues.
Sometimes the connection is running for 1 or 2 hours, sometimes it fails every 5 minutes. In all cases, it does not reconnect by its own. “Low signal reconnect” is enabled.
RSSI is an a “good” range.
I need to force reconnect by Teltonika App (disable/enable Interface) or WebUI (Restart Connection).

I checked antenna cable and position, no probblems and nothing changed compared to last year.

A week or two ago I updated to firmware RUTX_R_00.07.15
Issues seemed to occur less often.
Yesterday I updated to firmware RUTX_R_00.07.15.2
Issues seem to get worse, sometimes reconnecting using the App is not successfull and I need to do it twice or reboot.

Event log says (example):

2025-07-01 10:40:31
Health checker
Network
Notice
DNS resolution started to fail

2025-07-01 10:40:13
Health checker
Network
Notice
IPv6 connectivity started to fail

2025-07-01 10:40:10
Health checker
Network
Notice
IPv4 connectivity started to fail

2025-07-01 10:40:06
Mobile Data
Network
Info
Mobile data disconnected (internal modem)

Opertaional usage of the modem is currently not possible any more.
Any suggestions to get the problem solved?

Hello,

We’ve had a couple of clients with a similar issue to yours that were able to solve the problem by following the steps I’ve provided here:

Let me know if it works,
M.

Thanks for the advice.
I applied the changes and will see what happens …

I am having the same issue on both a trb245 and trb255 device with the same configuration and event logs reading the same.
In my case the only way to achieve a reconnect to the RMS is through a power cycle.
and also of note is the connection fails at the same time the isp assigns a new IP address to the two devices.
I would be very interested to know the outcome of editing the config in the network file via SSH/CLI was successful.

Hi there,

I would rate the solution as “partially”.

The main issue that the connection is not restoring automatically is solved. So a manual interaction is needed.

But the connection still fails and it takes a while to restore.
I checked the Event Log of this night (while no clients were connected to the router, so no traffic). Between “Mobile data disconnected (internal modem)” and reconnecting including IPv4 / “IPv6 connectivity restored” 5 minutes passed (see Event Log below).

Same situation when clients were connected this morning (see Event Log 2 below).

So when there is no continious traffic, you might not realize the time disconnected.
But for every application demanding a continious connection the solution is not sufficient.

Any further suggestions?

Event Log 1

5769 2025-07-04 05:25:50 Health checker Network Notice DNS resolution restored
5768 2025-07-04 05:25:50 Health checker Network Notice IPv6 connectivity restored
5767 2025-07-04 05:25:50 Health checker Network Notice IPv4 connectivity restored
5766 2025-07-04 05:25:23 Network Operator Network Info Connected to 26202 operator (internal modem)
5765 2025-07-04 05:25:23 Network Type Network Info Joined 5G-NSA network (internal modem)
5764 2025-07-04 05:25:23 Mobile Data Network Info Mobile data connected (internal modem)
5763 2025-07-04 05:25:20 Network Operator Network Info Connected to 26202 operator (internal modem)
5762 2025-07-04 05:25:20 Network Type Network Info Joined 5G-NSA network (internal modem)
5761 2025-07-04 05:25:20 Mobile Data Network Info Mobile data connected (internal modem)
5760 2025-07-04 05:25:07 Mobile Data Network Info Mobile data disconnected (internal modem)
5759 2025-07-04 05:22:02 Health checker Network Notice DNS resolution started to fail
5758 2025-07-04 05:21:44 Health checker Network Notice IPv6 connectivity started to fail
5757 2025-07-04 05:21:41 Health checker Network Notice IPv4 connectivity started to fail

Event Log 2

5795 2025-07-04 09:41:35 Health checker Network Notice IPv6 connectivity restored
5794 2025-07-04 09:41:35 Health checker Network Notice IPv4 connectivity restored
5793 2025-07-04 09:40:47 WiFi Connections Notice Harriet_5G: WiFi client connected: 98:5F:41:4C:F2:A7
5792 2025-07-04 09:40:42 Network Operator Network Info Connected to 26202 operator (internal modem)
5791 2025-07-04 09:40:42 Network Type Network Info Joined 5G-NSA network (internal modem)
5790 2025-07-04 09:40:42 Mobile Data Network Info Mobile data connected (internal modem)
5789 2025-07-04 09:40:40 Network Operator Network Info Connected to 26202 operator (internal modem)
5788 2025-07-04 09:40:40 Network Type Network Info Joined 5G-NSA network (internal modem)
5787 2025-07-04 09:40:40 Mobile Data Network Info Mobile data connected (internal modem)
5786 2025-07-04 09:40:35 Health checker Network Notice DNS resolution restored
5785 2025-07-04 09:40:26 Mobile Data Network Info Mobile data disconnected (internal modem)
5784 2025-07-04 09:36:35 Health checker Network Notice DNS resolution started to fail
5783 2025-07-04 09:36:17 Health checker Network Notice IPv6 connectivity started to fail
5782 2025-07-04 09:36:16 Mobile Data Network Info Mobile data disconnected (internal modem)
5781 2025-07-04 09:36:10 Health checker Network Notice IPv4 connectivity started to fail

Hello,

As I’ll need the full troubleshoot file from your device in order to pass it to the R&D for analysis, I’ve sent you a form to fill out so we can continue our conversation in private, to avoid accidentally leaking any sensitive information. In the Ticket ID field, simply enter the thread’s number, which is 14475.

Thank you,
M.

Hello, I have the same issue on a TRB140 F/W 7.15.2. Mobile signal and connection is fine and connects to RMS on power up/reboot but then disconnects within a matter of minutes. Error message within UI says ‘failed to resolve host name’ Please advise.

Hello,

“Failed to resolve hostname” just indicates that your device has disconnected from the internet completely.

Anything in particular must happen for the device to disconnect? What kind of environment are you using the device in? How are the signal strengths?

Regards,
M.

Hi Matas,

Signal strength is good -67dbm 4G connected to Vodafone. If we reboot the router, it connects no problem and then disconnects after a minute or so. I have tried a different 4G router with the same SIM and have no issues.

Let’s move to a private conversation then. I’ve sent you a form to fill out so we can continue our conversation in private, to avoid accidentally leaking any sensitive information. In the Ticket ID field, simply enter the thread’s number, which is 14475-2. Use the -2 to differentiate from the original ticket creator.

Thank you,
M.