[SOLVED] Warning at bootup of ubuntu server 18.04 Reinstall

[mhumm2]

After messing things up so badly, I had to reinstall US18.04. Here is the warning message I get:

mark@AMD-64:/$ ssh mark@nas-64
Warning: the ECDSA host key for 'nas-64' differs from the key for the IP address '2600:1700:e770:b7e0:ec4:7aff:fe4a:221b'
Offending key for IP in /home/mark/.ssh/known_hosts:1
Matching host key in /home/mark/.ssh/known_hosts:2
Are you sure you want to continue connecting (yes/no)?

I attempted to delete hosts:1 and rename hosts:2 to hosts:1 since I assume the reinstall ECDSA host key would be in hosts:2. My challenge is there is no /home/mark/.ssh/known_hosts:1 or 2 directories. Is my goal to delete hosts:1 and rename hosts:2 correct? If so, how do I do it?

[GreyGeek]

How did you re-install?
I.e., where did you get the ISO?
Did you checksum it and did it pass?
Did you make a LiveUSB stick or a LiveCD?
Did you run the check program on the one you made?
Did you destroy the exiting partitions and recreate them?
etc...

[oshunluvr]

Delete the offending ssh key and rebuild it, or simply rename .ssh to .ssh_old, make a new .ssh and copy your config over leaving the keys behind. How are you doing your ssh key creation?

https://www.ssh.com/ssh/copy-id

[oshunluvr]

Google works too:

https://superuser.com/questions/4210...ecdsa-host-key