i believe the dmx deck only communicated with the lynx usb dongle, programmed for dmx, sitting on a com port...
vixen should use only the etherdongle plugin, and nothing about dmx, or pixelnet.
to get my eD(EtherDongle) to work at first, i let it sit on the network for about 5 min, then i had to power cycle the eD (uplug, then plug back in)
most laptops within the past 5 years natively support the ability to plug into another device without first a switch. (MDIX)
If you have the eD plugged into your switch, and you can access that network via wired, or wireless, it shouldn't matter.