When using VMware Update Manager via ISA 2006 SP1 and using proxy authentication the HTTP 502 Error may be seen in the "C:\Documents and Settings\All Users\Application Data\VMware\VMware Update Manager\Logs\vmware-vci-log4cpp.log" log file:

[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 525] Downloading https://www.vmware.com/PatchManagementSystem/patchmanagement via proxy proxy.domain.com:8080
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 527] Proxy user: DOMAIN\Username
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 726] Status code: 502
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 ERROR]  [httpDownload, 762] Error retrieving document https://www.vmware.com/PatchManagementSystem/patchmanagement. Unhandled status code: 502

In addition, the following errors may be reported in VirtualCenter:

Failed to download host update metadata
Failed to download host update packages
Web site hosting the update signatures and update packages cannot be reached. Please test the internet connection from the client.

Specify the proxy server by it's IP address instead of it's fully qualified domain name.

From VirtualCenter:

- Click on the Update Manager button in the toolbar
- Select the Configuration tab
- Select Internet Access
- Enter the proxy server's IP address in the proxy field
- Ensure port, DOMAIN\username and password are correct and click Test connection.

Test connection will fail if the fully qualified domain name is used.

Running the job will now complete successfully:

[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 525] Downloading https://www.vmware.com/PatchManagementSystem/patchmanagement via proxy 192.168.1.10:8080
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 527] Proxy user: DOMAIN\Username
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 726] Status code: 407
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 848] Authenticate using proxy user: DOMAIN\Username
[YYYY-MM-DD HH:MM:SS:SSS 'httpDownload' 4824 INFO]  [httpDownload, 726] Status code: 200