Currently, I have SSH setup and I can SCP/SFTP files between them over wifi, but it's slow.

I'd love to be able to connect them with a cable (I have a Maxonar Thunderbolt 3/4, USB4, and USB-C Cable) and easily transfer files between them, without having to restart one of the macs in target disk mode to do so, or disrupt their internet connections.

Is there any way to do this, either a 3rd party program that enables it, a built-in method, or a way to make the Thunderbolt cable act as a network cable that would allow me to SCP/SFTP over it?

In case it makes a difference, one is a 2019 MBP running Monterey, and the other is a 2016 MBP running Mojave, both Intel processors.

  • What speed are you trying to get? - I just tried a Netperf test between two old Mac Minis (2014 & 2017) and in the TCP_STREAM test saw 939.8 Mbit/s over Gigabit network - Note that is pure network speed - No disk IO and no encryption (scp, sftp etc).
    – DavidT
    Oct 2, 2023 at 0:39
  • With SCP/SFTP over wifi, I currently get a max of about 10Mb/s, in a big part because neither machine is super close to the access point (although they are next to each other). Anything better than that would be awesome. I understand that thunderbolt 3/4 theoretically could go up to 5Gb/s on my machines (maybe even 10Gb/s or more, but I'm not sure). Oct 2, 2023 at 0:43
  • I don't know the answer to your original question, but I just ran another test - reading and writing a single large file (ISO) via NFS from a Mac to Linux box (hardwired) both directions were better than 400 Mbit/s (50 MBytes/s) so you may be able to get much better than you have now by just using a network switch
    – DavidT
    Oct 2, 2023 at 0:55
  • I would need to be hardwired (to the router/switch) to get those sorts of speeds I believe, and that's not currently practical, hence looking for a way to connect the macs directly to each other in place, ideally with a cable I already own Oct 2, 2023 at 0:57
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    @DavidAnderson You should really post this as an answer.
    – benwiggy
    Oct 2, 2023 at 8:41

1 Answer 1


I use a Thunderbolt 2 cable to connect between a 2011 iMac and a 2013 iMac. I had to manually configure the Thunderbolt Bridge on both machines. Below is an image of the configuration used. The left is the 2011 iMac and the right is the 2013 iMac. For a better view, either click on the image or open the image in a new window.

Two screenshots of the Network Preferences showing the TCP/IP settings for a Thunderbolt Bridge

I chose and because I thought these IP addresses would probably not conflict with any IP addresses issued by any DHCP servers in use. I can SSH, share folders (SMB) and screen share (VNC) over this bridge. I have not tested to see if this would work with Thunderbolt 3/4. However, user user1572284 did post comments (see here and here) stating success in using SMB over Thunderbolt 3 to mount certain USB drives.

  • 1
    That worked and I got the drive SMB mounted. Thanks! Oct 2, 2023 at 21:12

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