Sometimes with Windows 7 VDI desktops, the systems lose the IP address on the NIC when they are saved, and the NIC won't get a new one when it "wakes" back up.
Run this PowerShell on your hosts to see which VDI desktops have not been able to get an IP address when they unsaved (the IP addresses will all begin with 196.254.x.x):
Get-VM | Select -ExpandProperty NetworkAdapters | Select VMName, IPAddresses, Status
How to configure a Cisco UCS Chassis running version 4.0 firmware to use an internal certificate authority's SSL certificate
Building the Cert file to create a new Trusted Point in UCS
Creating the Trusted Point in UCS Manager
Applying a Certificate to a Dell iDRAC Controller when using an internal Enterprise CA using ADCS
Applying an internal SSL certificates to devices to make sure all devices can be opened easily and without warnings in all browsers. These directions have worked so far on all recent versions of iDRAC (7, 8, & 9). Note the Gotcha in step 6 when using an internal CA.