Use IP over Thunderbolt to connect Mac computers
Connect two Thunderbolt-equipped Mac computers using a Thunderbolt cable, then use Internet Protocol (IP) to communicate between the computers.
When you connect computers using a Thunderbolt cable, by default the computers receive IP addresses using DHCP. If needed, you can enter an IPv4 address manually.
Connect a Thunderbolt cable to the Thunderbolt ports on the computers you want to connect.
On your Mac, choose Apple menu > System Settings, then click Network in the sidebar. (You may need to scroll down.)
Click the Thunderbolt Bridge service on the right, then click Details.
If you don’t see a Thunderbolt Bridge service, you need to add one. See Set up a network service.
If you need to enter an IP address, click TCP/IP, click the Configure IPv4 pop-up menu, choose an option, then enter the IPv4 address in the IP address field.
If needed, you can also enter a subnet mask and router address.
If you need to enter DNS or search domain addresses, click DNS, then enter the addresses.
To transfer files between the computers, open a Finder window on one Mac, click Network below Locations in the Finder sidebar, double-click the icon for the other Mac, click Connect As, select a connection option, then click Connect. If you don’t see the other Mac, make sure it has file sharing turned on.