REMOTE HOST IDENTIFICATION HAS CHANGED! - The-Bioinformatics-Group/Albiorix GitHub Wiki

Sometimes when you try to access Albiorix you might see something like this:

mats@Slartibartfasts:~$ ssh -X [email protected]
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
The RSA host key for albiorix.bioenv.gu.se has changed,
and the key for the corresponding IP address 120.251.158.230
is unchanged. This could either mean that
DNS SPOOFING is happening or the IP address for the host
and its host key have changed at the same time.
Offending key for IP in /Users/mats/.ssh/known_hosts:3
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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 the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
4b:1e:98:2e:01:e7:3e:0c:69:95:77:23:1e:d2:91:15.
Please contact your system administrator.
Add correct host key in /Users/mats/.ssh/known_hosts to get rid of this message.
Offending key in /Users/mats/.ssh/known_hosts:3
RSA host key for albiorix.bioenv.gu.se has changed and you have requested strict checking.
Host key verification failed.

mats@Slartibartfasts:~$

This usually means that there is some maintenance work going on on Albiorix at the moment. For example, when a new login node is being installed, then this message usually occurs.

On your local machine you have a file called ~/.ssh/known_hosts, that keeps track of the "RSA host keys" of remote servers you have accessed. The first time you logon to Albiorix, you'll see something like this:

The authenticity of host 'pc178553.dpes.gu.se (183.261.178.553)' can't be established.
RSA key fingerprint is 4y:8e:19:7e:01:e4:3e:0s:64:93:73:93:5e:d2:91:17.
Are you sure you want to continue connecting (yes/no)?  

If you answer "yes" to this question, the "fingerprint" (i.e. the "RSA host keys") of Albiorix will be stored in the file ~/.ssh/known_hosts, and your computer will then recognise the cluster the next time you try to logon.

However, if there is no maintenance work announced on the mailing list, then there there is also the possible that someone is doing something nasty, as the error message says, and that you should contact the system administrator.