Last week I was troubleshooting some backup problems with a VM. For this reason, I wanted to access the ESXi directly with the VI client. After typing the root credentials, I received the following error message:

the vSphere client could not connect to … You do not have permission to login to the server: …

I thought that maybe someone played around with the permissions on the command line. So I enabled SSH for the ESXi server:

After this, I tried to login with SSH and received the following error message:

Access denied

After retrying with a lot of different users and passwords, I remembered that there is some kind of restriction mode to access the single esxi servers. Oh yes, the LOCKDOWN MODE -.-

After checking the options in the vCenter Server I saw it: The lockdown mode was enabled!

I then disabled it by login in to the vCenter Server and disabled it in the esxi configuration security profile by unchecking the box:

Right after disabling it, I could connect to the ESXi server with SSH and the VI Client:

So please remember to check the lockdown mode if you don’t want to lose too much time troubleshooting login problems 🙂