Due to our recent relocation of the Hummingbird cluster to our new datacenter facility up in Washington, users may experience an issue trying to connect to the server again for the first time after the move. This issue is due to us having to update the IP address of the systems.

The issue will look like either:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
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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:/YgVYo4Gdo9oTvdQLgFqKlXki3EOY7WWbPDzvxPnUCY.
Please contact your system administrator.
Add correct host key in /home/rkparson/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /home/rkparson/.ssh/known_hosts:7
ECDSA host key for amalthea has changed and you have requested strict checking.
Host key verification failed.

or

Warning: the ECDSA host key for 'hbfeeder.ucsc.edu' differs from the key for the IP address '128.114.102.155'
Offending key for IP in /home/rkparson/.ssh/known_hosts:1
Matching host key in /home/rkparson/.ssh/known_hosts:2
Are you sure you want to continue connecting (yes/no)?

If you experience this issue, you just need to run this command, to clear the cached login fingerprint that was used to identify our server:

ssh-keygen -R hb.ucsc.edu

After that, you should be able to SSH again as normal.

NOTE: This impacts hb.ucsc.edu as well as hbfeeder. ucsc.edu. For HBFeeder, use this command instead:

ssh-keygen -R hbfeeder.ucsc.edu