I've been using various versions of the Simulator on VirtualBox without too much issues. However with version 9.1 I'm getting weird network issues. I'm pretty sure there are ARP issues at the simulator side of things. My VirtualBox host (Mac OS Sierra) keeps sending ARP requests for the various IPs of the Simulator (node and cluster management). Sometimes it succeeds in getting an ARP request and I can see pings go out, but they are never returned. Sometimes I can see ARP requests coming from the Simulator asking for the MAC of the gateway, to which my Mac responds, but it seems like this is being ignored by the Simulator, because it keeps asking over and over.
These are Host_Only interfaces. Virtualbox is running the latest release, 5.1.22.
If I run other VMs with Host_only interfaces, they work just fine (Simulator 8.3.2, Ubuntu, whatever, all no issue). I'm using the Intel PRO/1000 MT Server nics as usual.