Chris sent me this question:

I have a load balancing team configured with 2 intel mt 1000 gigabit cards.
My guest operating system looses network connectivity If I leave it idle for say 10 minutes or if I close out and come back in after a while.

The information you need is here, basically you should try removing the team first and see if this resolves the issue, before contacting your hardware manufacturer.

Someone may have other suggestions, which they can comment on here.