I have an old early 2011 MBP and just got my new 2017 MBP last night. I also have the Elgato TB3 dock and was planning to set up my new MBP via gigabit ethernet from old to new via the dock. No matter what I tried I could not get it to work. I turned off wifi even to the point of deleting my password for the wifi network to try to force it to migrate over ethernet. It would just not work. So I turned wifi back on and tried to migrate via wifi, that also did not work. I then started to wonder if the fact that my old MBP's SSD is encrypted with FileVault was causing the problem. I'm now decrypting the SDD but that will take at least overnight. Any ideas, is the encryption the problem?