I can't find the list of supported NICs in the documentation, but I found https://github.com/SnabbCo/snabbswitch/blob/master/src/lib/hardware/pci.lua#L54 https:

I can't find the list of supported NICs in the documentation, but I found https://github.com/SnabbCo/snabbswitch/blob/master/src/lib/hardware/pci.lua#L54 https://github.com/SnabbCo/snabbswitch/blob/master/src/lib/h... which suggests that only a very small subset of Intel NICs are supported. One of those may be emulated by VirtualBox, though.