Issue
I am trying to SSH to my raspberry pi which is connected under the same router as my computer. It is running the latest version of raspbian lite. I enabled the ssh service on the pi using the command: systemctl enable ssh. However when I try to SSH to my raspberrypi from my personal computer, I get this message:
fahd@Fahd-PC:~$ ssh [email protected]
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ 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 ECDSA key sent by the remote host is
SHA256:***************************************************
Please contact your system administrator.
Add correct host key in /home/fahd/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /home/fahd/.ssh/known_hosts:1
remove with:
ssh-keygen -f "/home/fahd/.ssh/known_hosts" -R "192.168.1.23"
ECDSA host key for 192.168.1.23 has changed and you have requested strict checking.
Host key verification failed.
fahd@Fahd-PC:~$
And I'm not entirely sure whether this is something real I should be worried about or just me not knowing how to use SSH properly.
Solution
For some reason, your terminal has a different key in storage for your Pi. This can be due to several reasons (for example, the ssh package was updated and the SSH host key re-generated on the Pi. Or you changed the IPs on your network. Or you have DHCP and two different clients, and you got the addresses swapped. Or...).
So, it warns you.
Unless you have reasons to believe otherwise, I'd just follow the suggestion:
remove with: ssh-keygen -f "/home/fahd/.ssh/known_hosts" -R "192.168.1.23"
Answered By - LSerni