Today, I faced an issue that despite SSH service was running properly and Lockdown mode was not enabled, I was not able to connect to the ESXi host using SSH to perform some tasks. I restarted the SSH service again but the issue didn't get fixed. I was getting the error "Network error: Connection timed out."
The Fix
Upon checking, I found that in Firewall Properties (Remote Access) under Required Services, the SSH Server option was unchecked. I checked it and restarted SSH service once again.
SSH Server is checked by default, but if you uncheck it, SSH connectivity will not work. Another reason for this issue may be that Lockdown mode is enabled.