Problem

I was unable to connect to an ESXi host via SSH and HTTPS. However, DCUI still worked (and the host was still connected in vCenter) so we knew the password was correct

 

Troubleshooting

Logging in via the DCUI and connect to the ESXi Shell (ALT+F1)

Check the user is not locked out:

pam_tally2 --user root

Login           Failures Latest failure     From
root                1798     08:23            unknown

As you'll see I had 1798 failures. This is an internal facing machine.so it was something coming from th LAN

 

Reset the count:

pam_tally2 --user root --reset

I was now able to login but this didnt fix the issue long term as something was still failing to authenticate.

 

Solution

The log file /var/log/rhttpproxy.gave a bit more information.

It turns out our monitoring system had an incorrect password.when trying to connect for its checks