I had a issue today with running remote commands on one of my fabric switches, always generated an error.
apic1# fabric leaf02 show switchname ---------------------------------------------------------------- Node 102 (leaf02) ---------------------------------------------------------------- Error: Error executing command on leaf02. Error Code: 255
I tried to directly connect and found the error
admin@apic1:attach leaf02 This command is being deprecated on APIC controller, please use NXOS-style equivalent command # Executing command: ssh leaf02 -b 10.127.240.1 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ 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 d1:f1:c4:8a:3e:a7:df:4a:76:bf:ec:01:bb:0d:28:99. Please contact your system administrator. Add correct host key in /home/admin/.ssh/known_hosts to get rid of this message. Offending key in /home/admin/.ssh/known_hosts:2 Password authentication is disabled to avoid man-in-the-middle attacks. Keyboard-interactive authentication is disabled to avoid man-in-the-middle attacks. Permission denied (publickey,password,keyboard-interactive).
I think this was the switch that i converted to NX-OS standalone mode, and thus it changed the host key.
The fix is easy, open the file and delete the offending key
vi /home/admin/.ssh/known_hosts
After that i was able to run commands from the apic and also connect to the fabric switch again.