I use VirtualBox for a lab environment with VMs running various versions of Windows. One thing that keeps happening and I don't know why (never seen it before on my VMware servers) is that DNS connectivity will be loss between VMs. I can nslookup and that works, but ping doesn't, and no other app will be able to resolve the other VM. This happens either on bootup, or at random times while the VM is running. The only way to fix it is by:
net stop dnscache
net start dnscache
Right now I'm thinking it's either something to do with VirtualBox, or the fact that I'm cloning VMs (I do randomize MACs for each new VM). Anyone has seen this before?