Just a little tip in case someone else hits this. If you have an ESX host that can’t scan for updates or gets the following error in vCenter check the DNS config:
Host cannot download files from VMware vCenter Update Manager patch store. Check the network connectivity and firewall setup, and check esxupdate logs for details.
This can be caused by having the wrong DNS server listed or none at all.
Based on Orignial article located here: http://technet.microsoft.com/en-us/library/cc431377.aspx#Config_RequestFiltering
Configure requestFiltering for IIS on distribution points
Use the following procedure to modify requestFiltering for Windows Server 2008 and Windows Server 2008 R2.
vmware-vdiskmanager -r "C:\vms\Windows XP\windows xp.vmdk" -t 6 -h esxi.sanbarrow.local -u root -f passwordfile