When using PowerCLI, the first thing you have to do is to create a connection and authenticate yourself to your vSphere and/or vCenter servers. This is done with the Connect-VIServer cmdlet. Sometimes, this connection can be slow, taking ten or more seconds just to display a password prompt! That gets old pretty quickly.

There is a good reason for the slowness before you are prompted for credentials, and turns out, it’s a feature, not a bug. PowerCLI supports a single-sign-on (SSO) authentication when you attempt a connection to a vCenter server. What happens in the background is that your current Windows credentials are being passed on to the server and that is tried first, before even prompting you for credentials. This is great if you are sitting at the office and have a fast link to the vCenter server, and you happen to be logging into your workstation with a domain accont, and that domain account has vCenter rights. This transparent passing of credentials is definitely a timesaver under those circumstances.

But on the other hand, what if you are connecting from home over a slow link? What if you are on your home PC or a local account? What if, due to security policies at your company, your normal user account doesn’t even HAVE admin privileges? Yup, the authentication attempt fails (or simply takes a while), and you are left twiddling your thumbs, waiting for the “real” login prompt to appear.

Resolution

The fix is an easy one. Instead of typing this to connect:

Connect-VIServer vcenter.domain.com

…type something like this:

Connect-VIServer vcenter.domain.com -Credential (Get-Credential)

or the less-recommended, yet still quite functional:

Connect-VIServer vcenter.domain.com -user myuser -password mypass

By using one of these methods, you are instructing Connect-VIServer to explicitly use a set of credentials which you specify. This way, it won’t bother attempting to pass along your current credentials, thus saving you a few seconds and perhaps a gray hair or two.