Event ID 16: Windows Update Client ignoring proxy settings

Question

Have a couple of locked down, standalone Windows 2008 R2 servers (not on a domain; no WSUS) that refuse to adhere to the proxy settings each morning at around 4:25AM EST with what I'm assuming is a probe to check for updates:

Unable to Connect: Windows is unable to connect to the automatic updates service and therefore cannot download and install updates according to the set schedule. Windows will continue to try to establish a connection.

Funny thing is, the "you have updates" balloon always appears when there's indeed updates and "Check for Updates" always works fine. It's just some errand, scheduled probes that ignore the proxy for some reason, hits the firewall, and emails me an alert.

Really would like to quiet this down, but I'm at a loss as to where/why that's happening. Is there a bit I can flip in the registry to tell it to stop?

EDIT

Proxy is configured manually through Internet Explorer and as I've said, works fine.

netsh winhttp show proxy returns the correct proxy settings as well.

Solution

Ended up disabling Automatic Updates from doing any automated checks. I now do checks, downloads, and installs completely manually at set maintenance intervals each month and since then, servers are whisper quiet.

Comments

[growse]

How are you setting the proxy? Through IE?

[gravyface]

In IE, and also through net sh for system-wide proxy settings.

[dakira]

Any authentication on the proxy? NTLM in particular can be bothersome

[Selivanov Pavel]

Is there something interesting in proxy logs about this server?

[Paul Ackerman]

I had this problem once with Websense. Had to do with the time on the appliance not matching the server performing updates. Fixed the time sync on the appliance to resolve the problem.

[Garrett]

Bounty expired while I was writing my post?... Dang...

[gravyface]

And clearly you didn't read the question thoroughly or you would've seen that I've (obviously) already configured the system proxy settings with winhttp set proxy.

[Garrett]

Well, Event ID 16 only happens when the settings are bad, authentication fails, or the network connection is broken. I suggest you engage Microsoft if you think you found a bug.

[gravyface]

Is this not the same as defining system-wide proxy settings with netsh winhttp?

[Sven]

I am not sure. I have configured the Machine-based proxy and if I query the netsh winhttp setting, it tells me "Direct Access". Still all internet traffic flows through our proxy.