Teletonika RUTX50 MTU value Change

[PatrickF]

Hey,

I try to implement a openVPN connection from a PC to the RUTX50. On PC I got openVPN GUI running.

Certification seems ok but I get a “bad encapsulation” error. Had this problem in another set-up too, so I need to change the tun-mtu parameters on .ovpn (client and server).

With ping -f -l I found the best MTU parameter with 1460. So I changed in client.ovpn tun-mtu to 1460.

But I can’t change in rutx50 server. In webUI there is no Parameter like mtu. I can change it in wan interface, but this is somehow overwritten all the time. I also tried to change the server.ovpn in CLI, but every time when I start the openvpn again, ist is resetted to 1500. In openvpn Server log you can read that it is setting the MTU value to 1500.

What am I missing? Any idea? Why is it not possible to change this in rutx50?

Thanks a lot for your help

[Martynas]

Hello,

Could you try adjusting the MTU size by using this option in the server’s configuration file at /etc/config/openvpn?

option link_mtu ‘<your_mtu>’

This may allow you to set the desired MTU without it reverting back to 1500.

Best regards,