Internet Connectivity throttles down or even break after continuous connection

[Paule96]

Similar to #11983 I have the issue that I see very often (around after 24h of stable connection) something like that:

5567;2025-05-26 05:09:53;Health checker;network;notice;IPv4 connectivity started to fail
5568;2025-05-26 05:09:56;Health checker;network;notice;IPv6 connectivity started to fail
5569;2025-05-26 05:10:14;Health checker;network;notice;DNS resolution started to fail
5570;2025-05-26 05:11:15;Health checker;network;notice;IPv4 connectivity restored
5571;2025-05-26 05:11:15;Health checker;network;notice;IPv6 connectivity restored
5572;2025-05-26 05:11:15;Health checker;network;notice;DNS resolution restored
5573;2025-05-26 06:09:47;Health checker;network;notice;IPv4 connectivity started to fail
5574;2025-05-26 06:09:51;Health checker;network;notice;IPv6 connectivity started to fail
5575;2025-05-26 06:10:09;Health checker;network;notice;DNS resolution started to fail
5576;2025-05-26 06:11:09;Health checker;network;notice;IPv4 connectivity restored
5577;2025-05-26 06:11:09;Health checker;network;notice;IPv6 connectivity restored
5578;2025-05-26 06:11:09;Health checker;network;notice;DNS resolution restored
5579;2025-05-26 07:09:45;Health checker;network;notice;IPv4 connectivity started to fail
5580;2025-05-26 07:09:48;Health checker;network;notice;IPv6 connectivity started to fail
5583;2025-05-26 07:10:06;Health checker;network;notice;DNS resolution started to fail
5584;2025-05-26 07:11:06;Health checker;network;notice;IPv4 connectivity restored
5585;2025-05-26 07:11:06;Health checker;network;notice;IPv6 connectivity restored
5586;2025-05-26 07:11:06;Health checker;network;notice;DNS resolution restored
5587;2025-05-26 07:27:21;Health checker;network;notice;IPv6 connectivity started to fail
5588;2025-05-26 07:28:22;Health checker;network;notice;IPv6 connectivity restored
5589;2025-05-26 08:09:53;Health checker;network;notice;IPv4 connectivity started to fail
5590;2025-05-26 08:09:57;Health checker;network;notice;IPv6 connectivity started to fail
5591;2025-05-26 08:10:15;Health checker;network;notice;DNS resolution started to fail
5596;2025-05-26 08:11:26;Health checker;network;notice;IPv6 connectivity restored
5597;2025-05-26 08:12:44;Health checker;network;notice;IPv4 connectivity restored
5598;2025-05-26 08:12:44;Health checker;network;notice;DNS resolution restored

If the route is in this state he has maximum download bandwidth of 5mbits but a quite normal upload bandwith of 50mbits.
The ping response times are then above 2 seconds. This is for most application a not usable internet connection.

The interessting thing is, that a router reboot fixes the problem and brings me back to sub 40ms response times and download speeds above 400mbit.

I hope this issue can be fixed.

Router metadata:

Model: RUTC50
Firmware: RUTC_R_00.07.14.3
Modem Firmware: RG520NEBDCR03A04M4G_01.200.01.200
Provider: Telekom Germany
RSSI: -71 (Average)

[Martynas]

Hello,

Thank you for reaching out.

As a first step in troubleshooting this issue, could you please run the following commands via the router’s CLI/SSH and let me know if the initial issue with periodic connectivity loss still persists afterward?

uci set network.mob1s1a1.dhcp='0'
uci commit network
/etc/init.d/network restart

In case the issue still occurs, we’ll need to reach out and continue investigating the issue privately. Let me know the outcome here.

Best regards,

[Paule96]

Okay so far the command worked.

root@router:~# uci set network.mob1s1a1.dhcp='0'
root@router:~# uci commit network
root@router:~# /etc/init.d/network restart
{
        "state": "OK"
}
root@router:~# uci get network.mob1s1a1
interface
root@router:~# uci get network.mob1s1a1.dhcp
0

Will come back in like two to three days to report if the issue is gone.

In the maintime, can you explain what this setting is doing?

[Paule96]

The fix definitely changed something but didn’t fixed the problem. Here are the new logs that I see:

5540;2025-05-27 03:20:09;Health checker;network;notice;IPv4 connectivity started to fail
5541;2025-05-27 03:20:12;Health checker;network;notice;IPv6 connectivity started to fail
5542;2025-05-27 03:20:13;Mobile Data;network;info;Mobile data disconnected (internal modem)
5544;2025-05-27 03:20:30;Health checker;network;notice;DNS resolution started to fail
5545;2025-05-27 03:20:35;Mobile Data;network;info;Mobile data connected (internal modem)
5546;2025-05-27 03:20:35;Network Type;network;info;Joined LTE network (internal modem)
5547;2025-05-27 03:20:35;Network Operator;network;info;Connected to xxxxx operator (internal modem)
5548;2025-05-27 03:20:36;Mobile Data;network;info;Mobile data connected (internal modem)
5549;2025-05-27 03:20:36;Network Type;network;info;Joined LTE network (internal modem)
5550;2025-05-27 03:20:36;Network Operator;network;info;Connected to xxxxx operator (internal modem)
5551;2025-05-27 03:21:30;Health checker;network;notice;IPv4 connectivity restored
5552;2025-05-27 03:21:30;Health checker;network;notice;IPv6 connectivity restored
5553;2025-05-27 03:21:30;Health checker;network;notice;DNS resolution restored
5554;2025-05-27 03:25:35;Health checker;network;notice;IPv6 connectivity started to fail
5555;2025-05-27 03:27:39;Health checker;network;notice;IPv6 connectivity restored
5556;2025-05-27 03:43:50;Health checker;network;notice;IPv6 connectivity started to fail
5557;2025-05-27 03:44:50;Health checker;network;notice;IPv6 connectivity restored
578;2025-05-27 08:13:59;Mobile Data;network;info;Mobile data disconnected (internal modem)
5579;2025-05-27 08:14:11;Mobile Data;network;info;Mobile data connected (internal modem)
5580;2025-05-27 08:14:11;Network Type;network;info;Joined 5G-NSA network (internal modem)
5581;2025-05-27 08:14:11;Network Operator;network;info;Connected to xxxxx operator (internal modem)
5582;2025-05-27 08:14:13;Mobile Data;network;info;Mobile data connected (internal modem)
5583;2025-05-27 08:14:13;Network Type;network;info;Joined 5G-NSA network (internal modem)
5584;2025-05-27 08:14:13;Network Operator;network;info;Connected to xxxxx operator (internal modem)
5590;2025-05-27 08:29:13;Health checker;network;notice;IPv6 connectivity started to fail
5591;2025-05-27 08:30:16;Health checker;network;notice;IPv6 connectivity restored
5592;2025-05-27 08:37:19;Health checker;network;notice;DNS resolution started to fail
5593;2025-05-27 08:38:27;Health checker;network;notice;IPv4 connectivity started to fail
5594;2025-05-27 08:38:32;Health checker;network;notice;IPv6 connectivity started to fail

The following notes to the log:

• now almost always a reconnect on the modem happens if the IPvx connection is broken
• The connection is still not stable (and slow)

[Martynas]

Hello @Paule96,

Thank you for the update. I believe, to assist you effectively, we’ll need to continue this process privately. You should find a support request form in the inbox of the email address you used for your forum registration. Kindly fill out the form, and please reference Ticket ID: 13937 when submitting it. Once the form is completed, we’ll contact you directly via email to investigate the issue in detail and help work towards a solution.

Best regards,

[Paule96]

@Martynas It looks like your comment was the solution.
But the missing part was that the router needs a reboot before your fix works. Just restarting the network stack is not enough.

[Martynas]

Hello @Paule96,

Thank you for the update. Great to hear that the initial issue seems to be resolved, and thank you for noting the additional reboot action for it to work. Theoretically, option dhcp '0' is added and saved to the config immediately after running the suggested commands; however, it’s always recommended to reboot the device after any configuration change is made to test and ensure it works when it’s freshly booted.

I assume this thread can be closed now, or if you need any further assistance, please let me know.

Best regards,