Migration Assistant not recognizing ethernet

I am currently migrating from a MacBookPro to a desktop.

The desktop is running Sierra and the MacBookPro is running Yosemite. The desktop is a late 2013 (I think) and the MacBookPro I'm not sure. (I think it's 2010 perhaps. can't check because it is currently migrating).

Anyhow, they both have Ethernet ports and I have successfully plugged in an Ethernet cable between them. (complicated task, I know)

However when I use Migration Assistant, it always falls back on wifi, and says it's going to take 155 hours to transfer. I know the Ethernet cable is good, hence I'm using it currently (remember I already figured it out) and I was not able to connect using wifi.

How can I get Migration Assistant to use the Ethernet connection?

Okay, here we go

It's a simple answer, so...

After wasting hours of time trying to figure this out I realized that Migration Assistant is not smart enough to set up the Ethernet connection itself.

I had to go into System-Preferences->Network and add and manage the Ethernet.

I then turned off the wifi, turned on file sharing, and was able to see the other computer coming from the other side.

Even though all the tutorials I had read said "just plug in the Ethernet cable and go" (in my own words), I still had to set it up manually. Oddly enough, the MacBookPro didn't even have the default Ethernet settings.

Hope this helps someone else!