Fixing SSH Remote Host Identification Has Changed Warnings

SSH key authentication is a secure method of connecting to your server via SSH. When the SSH host key that is utilized for a connection changes and you attempt to connect to the server using the old host key's information an error similar to the one below will be produced.

Please note that values such as the fingerprint, username, SSH host key path, IP addresses, and other information shown below will differ as these are unique to your server or account.
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 RSA key sent by the remote host is
Please contact your system administrator.
Add correct host key in /Users/jsmith/.ssh/known_hosts to get rid of this message.
Offending RSA key in /Users/jsmith/.ssh/known_hosts:12
RSA host key for has changed and you have requested strict checking.
Host key verification failed.

On many systems the known_hosts file contains the listing of previous connected hosts along with the public key associated with said connection. Each time a user connects with an new or unknown host its public key is added to this file. Some systems and software applications can use other components to store this information as well. If the related public host key stored in known_hosts, or the equivalent component, no longer matches the SSH host key on your server: the above warning, or a similar warning for your software of choice, will be displayed.

Sometimes this message can be an indicator of a compromise if you know that no legitimate changes to the SSH host key have been made. This is not always the case though. In instances where known changes are made, such as re-creation of the SSH host keys for your server or the redeploy of the server itself, this error simply means that your locally stored SSH host key information needs to be updated to match the new SSH host key utilized on the server.

If you are uncertain if your server has been compromised or whether the host key has just changed, and you have service with us, please contact our support team.

Follow the directions below to resolve this issue.

Windows SSH Client PuTTy Bitvise MacOS or Linux