I have set up ssh key pairs between my desktop and two servers, and from the servers to my desktop, but after reinstalling the OS on my desktop, I can\'t re-establish the key-pa
Its means your remote host key was changed (May be host password change),
Your terminal suggested to execute this command as root user
$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231
You have to remove that host name from hosts list on your pc/server. Copy that suggested command and execute as a root user.
$ sudo su // Login as a root user
$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231 // Terminal suggested command execute here
Host [www.website.net]:4231 found: line 16 type ECDSA
/root/.ssh/known_hosts updated.
Original contents retained as /root/.ssh/known_hosts.old
$ exit // Exist from root user
$ sudo ssh root@www.website.net -p 4231 // Try again
I Hope this works.