Can't login to webui, ssh is ok


I had to replace a RUT240 with a RUT241 lately. After the latter was installed in the remote place, I couldn’t login to the webui anymore.

I have a working wireguard connection to the router, and access over ssh with user root is ok.

When I try to access the webui with the user admin, I get an error ‘Invalid username and/or password! Please try again.’

I have reset the password for the user admin over ssh, restarted the webserver, but still can’t login.

This is with Firefox as browser. With other browsers, a file (with garbage) gets downloaded.

Anything else seems to work fine, so I would prefer not to restart the router remotely, as if something else goes wrong, half the next day will be lost to fix it (the router sits 1.5 hour away from here).

The firmware on the router is RUT2M_R_00.07.07.1. Another RUT241 router with fw RUT2M_R_00.07.07 is working fine.

Thank’s in advance for any help


This might be a MTU issue. What are the values of the wan or qmimux0 interface and of the wireguard interface ?
What is the output of:

gsmctl -A "AT+QMTUINFO"


root@xxxxxxxxxx:~# gsmctl -A “AT+QMTUINFO”

It outputs the error above.

MTU of qmimux0 is 1464 and MTU of wg01 is 1420.

The values are the same on another RUT241 connected to the same wireguard “gateway”, which is doing fine.

Thank you and regards

The error is there the MTU of the wg interface must be less than 1464 - 80 = 1384.
Just in case IPv6 conversions appear somewhere in the path in the future, limit it to 1280 bytes.

So far I only changed the MTU on the WG-gateway to 1352 and will change it on the two RUT242 too when when I get a chance to go to the external places (I would not like to shoot myself in the knee…).
The change on the gateway helped, the webui is accessible now.
Many thanks for your suggestion and help.
With best regards

This topic was automatically closed 40 hours after the last reply. New replies are no longer allowed.