Just got this from our VMware guy. I thought I should pass it along. Mods, if this should be someplace else let me know.
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If you have VMXNet3 currently deployed, this may affect Windows 7 SP1 & Windows 2008 R2 VMs with the recent rollup update released by Microsoft in April 2016.
Microsoft release:
A new Ethernet vNIC may be created with default settings in place of the previously existing vNIC, causing network issues. Any custom settings on the previous vNIC are still persisted in the registry but unused.
Please note the following post: http://blogs.vmware.com/apps/2016/06/rush-post-microsoft-convenience-update-and-vmware-vmxnet3-incompatibilities.html
Microsoft’s description of the issue and current workaround: https://support.microsoft.com/en-us/kb/3125574
Please treat this matter with importance due to the stability and reliability of your virtual environment.
VMware is aware of this issue and we are actively investigating the root causes and possible fixes. While this effort progresses, VMware is advising customers to delay applying the Microsoft “Convenience Update” to any virtual machine that uses the VMXNet3 vNIC type.