virtualbox.org

I run VirtualBox 4.3 on my Mac and have a Windows 7 guest. The Windows 7 guest network adapter doesn't get an IP after most resumes. I don't pause the VM but just put the computer to sleep. I resolve this by switching back and forth between a NAT and Bridged ethernet adapter.

Does anyone have advice that would eliminate me swapping the adapter type back and forth?

Yes. Either shut down the guest before putting the host to sleep, or save its state. I'm not sure that the latter will work although. Or, actually come to think of it, in 4.3.x versions if you click on the network icon you can quickly "disconnect" and "connect" the network cable (the check mark next to the connection). That will force the guest OS to renew its address.

Reason: When a computer goes to sleep, it's a combination of software and hardware events that notify the OS, and the OS can take appropriate action. Now, in the guest, it's a different story. The guest simply "freezes" in time without any notification whatsoever. When it wakes up from "hibernation" it is definitely some time later in the future and possibly in a different network.