Device loosing connection when connected to RUT300

I have the following device setup:

  1. Access router from internet provider, lets call it “Access router”
  2. RUT300 Teltonika router, connected via cable to router #1
  3. Test device, let’s call it device X, connected via cable to RUT300

And now, I connect device X to RUT 300 and test if it has internet connection. Device X has an application that is calling external servers via TCP and additionally has a ping command available. Neither is working.
Now, I switch the device X to access router, by skipping RUT300. Everything works perfectly.
After that I switch device X back to RUT300 and surprisingly it works fine as well. Both the TCP connection to servers and ping command.
But after 5-15 minutes it stops working again.
This scenario is repeatable.

The RUT300 router doesn’t have any custom configuration. It’s a device freshly out of the box. I just updated the OS to newest one: RUT30X_R_00.07.07.1.

The device X doesn’t have any special network config as well. It’s set to accept params from DHCP.

How can I figure out what might be happening here?


To determine the root cause of this issue, we’ll need the troubleshoot file. Since it contains private information, we’ll handle it on a separate platform. Instructions for accessing it have been sent to the email you registered for this forum.

Best regards,

Hi @Marijus
Thanks a lot for reaching out!
I just filled the form and I have details problem description along with timestamps of my actions and troubleshoot file.
I’m waiting to receive information how to send it to you.


I’ve reached out to you via email. Feel free to attach troubleshoot and other files when you respond to that email.

Best regards,

Already done.
Thanks in advance!


I’ll examine the files and provide my feedback on the gathered information in this forum post.

Kind regards,

Just as an update.
I was in contact with Teltonika support and they advised to test the connection by adding an unmanaged switch between RUT300 and device X. It helped.
Teltonika R&D team is now looking for the reason.