RUT241 udhcp renew doesn't work

[Katrin]

I’ve got RUT241 Modems with the latest firmware.
One of them doesn’t get an answer to udchp renew.

Usually I get this every hour in the logs:
389 Wed Jun 4 15:42:34 2025 daemon.notice netifd: mob1s1a1_4 (4343): udhcpc: broadcasting renew
390 Wed Jun 4 15:42:34 2025 daemon.notice netifd: mob1s1a1_4 (4343): udhcpc: lease of 172.31.196.114 obtained from x.x.x.x, lease time 7200

The other modem just doesn’t get the lease information. Retries of the renew later are not successful either until the lease times out and then there is one final discover and then no connection until reboot.
I put that same sim card in a different RUT241 and it works.
Nothing interesting to see in /tmp/mobile/mobifd.log

Both RUT241 the same hardware and
both Firmware version RUT2M_R_00.07.15

What can be done to repair that?

[MatasR]

Hello,

I’d like to view the logs of the troublesome router. 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 14309.

Thank you,
M.

[MatasR]

Hello,

The issue has been resolved by editing the /etc/config/network file, and adding option dhcp '0' to the mob1s1a1 interface.

Here are the steps to make this change:

1. Log in to your router via SSH/CLI (more details here: Command Line Interfaces RutOS - Teltonika Networks Wiki)
2. Run the command vi /etc/config/network
3. Locate config interface 'mob1s1a1' and press “i” to enter edit mode
4. Add the line option dhcp '0' under the mobile configuration section
5. Press “Esc” , then type :wq and hit Enter to save and close the file
6. Afterward, you can execute /etc/init.d/network restart command to apply the changes and restart the configurations.

Regards,
M.