title: Can't connect from outside to guest [VirtualBox]
body: <p>In my workplace all machines' MAC addresses need to be extra unlocked by the IT staff in order to access the network and internet. </p>
  
  <p>I want to setup a test server in a VM in VirtualBox which should be accessible from inside the network/subnet. 
  In order to achieve this I thought about using a bridged network adapter with a manually specified MAC address borrowed from a currently turned off machine. </p>
  
  <p>This results in the following signal flow: </p>
  
  <p>[HOST] &lt;--> [GUEST]: ping to guest isn't working but accessing the guest through other means works</p>
  
  <p>[Outside HOST] --> [GUEST]: connecting to the guest from other network machines doesn't work at all. </p>
  
  <p>The GUEST correctly gets an IP-address in the correct subnet and can also connect to the Internet.</p>
  
  <p>The machine of which I borrowed the MAC address normally can connect to the HOST and vice-versa. </p>
  
  <p>I've tried both Windows &amp; Mac OS X hosts and Windows &amp; Linux guest with the same result. </p>
  
  <p>I've tried exactly the same configuration at home and here it's possible to connect to the VM from other network machines. </p>
  
  <p>I know I could use a NAT adapter with port forwarding, what indeed works, but it's cumbersome to manually add all of the used ports.</p>
  
  <p>Is it possible that the strict network restriction at my workplace can somehow detect that two MAC addresses are being used through one NIC on the HOST (the one from the virtual adapter and the physical one) and thus blocking the incoming traffic?</p>
  
  <p>If yes is is it possible to trick the corporate firewall to think that the VM is a legitimate physical machine?</p>
  
  <p>Thank you</p>