[SOLVED] VirtualBox: Network Suddenly Stopped Working on All Virtual Machines

My network suddenly stopped working for all virtual machines, while I was trying to setup vmail.

vmail - The virtual mail server

I tried rebooting the machines, checking the host network (which works), and checking the router configuration. None of these steps seem to work. What could be going wrong? How do I fix it?

Since it happened to all the VMs, I'd double-check the adapter settings for them (starting with just one of them) in VirtualBox. If it's set to NAT, change it to Bridged. If it's set to Bridged, test it with NAT.

It belongs on bridged - won't work properly with NAT. It's on bridged already and the proper configuration in DHCP is in the router already.

It belongs on bridged - won't work properly with NAT.

Do you mean it doesn't work on NAT or doesn't work the way you want it to on NAT.

If it's the latter, testing it on NAT may provide some clues as to the next troubleshooting step.

Please do not take this the wrong way, but you won't be able to shoot the trouble unless you are willing to test stuff.

All my Vboxen are bridged.

Just sayin'

I was going to go ahead and try NAT, but it seems the problem fixed itself. I know they wont work the way they need to on NAT, because they are servers designed to provide network services to my whole network, and the internet, and id already found that out by trial and error. But as you said, to troubleshoot, I was willing to try it. However, after restarting nearly all virtual machines, saving the last one for now, and then shutting them down and then rebooting the physical machine, then restarting all of them again, it seems to be okay again.