Error with SSH

[Ferrarista]

I have an Asus AX88U with the Merlin 388.4 firmware. I have just reset it to factory settings (and then restored manually all the settings including the VPN). When trying to access the router remotely with SSH (via VPN) I'm getting the following error

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ED25519 key sent by the remote host is
SHA256:xxx.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ED25519 key in /root/.ssh/known_hosts:2
  remove with:
  ssh-keygen -f "/root/.ssh/known_hosts" -R "[192.168.2.1]:40000"
Host key for [192.168.2.1]:40000 has changed and you have requested strict checking.
Host key verification failed.

What's wrong???

 

[Viktor Jaep]

I have an Asus AX88U with the Merlin 388.4 firmware. I have just reset it to factory settings (and then restored manually all the settings including the VPN). When trying to access the router remotely with SSH (via VPN) I'm getting the following error

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ED25519 key sent by the remote host is
SHA256:xxx.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ED25519 key in /root/.ssh/known_hosts:2
  remove with:
  ssh-keygen -f "/root/.ssh/known_hosts" -R "[192.168.2.1]:40000"
Host key for [192.168.2.1]:40000 has changed and you have requested strict checking.
Host key verification failed.

What's wrong???

I know that on new installs, my PuTTY will complain that the signature doesn't match with what is was connecting with before, and just downloads/saves a new one. Then it never complains again. Could it be something similar? What are you using to connect to SSH?

Have you tried running that command?

 

[Ferrarista]

Not yet, as I thought there was something to worry about.

To connect I'm using an Ubuntu shell under Windows 11 from remote (I'm not inside the physical network).

 

[Viktor Jaep]

Not yet, as I thought there was something to worry about.

To connect I'm using an Ubuntu shell under Windows 11 from remote (I'm not inside the physical network).

I would probably assume isn't not an attack, but as it mentioned, the host key just changed due to your factory reset.

 

[ColinTaylor]

What's wrong???

Nothing. The router generated a new key after your factory reset. Your client sees that this key is different than the one it used before. It's just warning you.

 

[Ferrarista]

So will the recommended command solve the issue?

 

[ColinTaylor]

Yes.