I did something I thought was a little dodgy in my DHCP server config, namely I assigned the same IP address to both the Ethernet and Wi-Fi MAC addresses for my laptop. I figured this was OK so long as I turned one off before turning on the other. Today, I tried breaking that rule. I started a large rsync transfer over wi-fi, decided it was too slow, and plugged in an Ethernet cable. And it worked! After a few seconds, I was able to turn off the wi-fi, and the transfer continued without a hiccup. Has anyone else tried this?