This is my setup: Two Macs (M1 2020, Mini 2018), connected with a Thunderbolt 3 cable. When both are running Big Sur, they have a working IP connection.

However, if I boot the M1 Mac into Recover Mode, it connects to the network only via Wi-Fi, but not over the TB3 connection.

When I enter Terminal on the M1, ifconfig lists many interfaces, but I can't tell if the TB interface is amoung them. Clearly, it shows no IPv4 address for any but the Wi-Fi interface, though.

What commands do I have to enter to enable the IP-over-TB interface and get it up so that I can connect the Macs via this faster connection?


1 Answer 1


My setup: two M1 MacBook Pro 16“ with Monterey 12.2.1

Problem: if you use the standard Migration Assistant workflow, it takes a couple of hours because they use Peer-to-Peer Wifi network with 20MBit - even though there is one Thunderbolt4 cable connection between the machines. Whatever I did, it always used this super slow connection. Searched the internet for a proper solution but did not find anything.

But okey, I got this solved - at least it worked for me (photo evidence)! I have two M1 16'' MBP and need to migrate from the 500GB SSD (MPB1) to 1TB SSD (MPB2) version. Purchased a Thunderbolt4 cable today at the Apple Store.

What I did after a couple of fails and searches on the net:

  1. MBP2: startup MBP2 and setup one admin user, skip all iCloud and whatever setup steps
  2. plugin Thunderbolt4 cable to both MBP1 and MBP2
  3. MBP2: go to network settings and add a fixed IP address to the Thunderbolt Bridge, for example and network mask (no router)
  4. MBP2: Activate Internet Sharing on MPB2 and share the Thunderbolt Bridge for Clients on Wifi -> the MPB2 will now open up a WiFi network, good idea to check the wifi settings and change the password to your own needs
  5. MBP1: startup the standard user and set the IP Address of the Thunderbolt Bridge to
  6. MBP1: connect to the MBP2 shared wifi network too (normally named after the computers name eg "MacBook Pro")
  7. MBP2: start the Migration Assistant and start just like you would do normally (migrate from another Mac, Volume, TimeMachine)
  8. MBP1: start the Migration Assistant and select "transfer to another Mac"
  9. Actually the macs now recognized each other and selected the fastest interface for the transfer - the Thunderbolt Bridge with 1686 MB/s!
  10. Choose whatever you want to transfer.
  11. I discovered the highest transfer rate was at 423 MB/s!
  12. Unfortunately I did not stop the time, but I think it took around 30mins to transfer 460GB.

I think it is a big advantage, that both macs don't use another wifi and you have the Thunderbolt Interfaces with fixed IPs. That should do the deal!

Side fact: USB-C cables are USB cables. Correctly recognize Thunderbolt 4 Cables by the printed Lightning Logo on the plug. Everything else is "only" USB3 ...

I did not try it using the USB-C cable - but I assume it works, only the network interface is named differently in steps 3 and 5.

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  • Congrats on figuring this out. However, what you describe is well-known behavior: If you start up both Macs with a regular macOS version and then connect them over their TB cable, then you can transfer files quite fast between them (Migration Assistant is just one app of many at that point). My particular problem was to get the connection working when I have NOT started into a regular system but am in the Recovery system where I cannot easily set up the Network. Still, your answer may be useful to others, so I'll leave it here. Commented Feb 11, 2022 at 23:00
  • You‘re right, Thomas! Actually it ShOULD work with current Migration Assistants and Thunderbolt4 Cable. But it doesn’t! Connect the cable and the MA is ALWAYS using the 20Mbit wifi peer-to-peer connection. No idea why, seems to be a bug between two M1 devices from my understanding. You even cannot use the new mount volume function (which was Target Mode earlier). Volume doesn’t show up in MA. So if you dont want to wait 14 hours for the slow transfer, you have to figure out how the M1 macs recognize each other voa the T4 connection.
    – JoochenC
    Commented Feb 12, 2022 at 6:27
  • Oh, and I found your entry, because I wanted to set the IP for the thunderbolt bridge in recovery mode too. But it isn’t possible from scratch, because the „networksetup“ is not part of the recovery system. I could imagine having it on a USB stick, and copying it to the recovery system, if you have sudo rights. Anyway its not easy, if possible … you can check the interfaces with netstat to at least read what’s going on. But ofcourse you want to set the IP for the TB bridge … hope I was of help a little …
    – JoochenC
    Commented Feb 12, 2022 at 6:47
  • 1
    This is the one you were looking for, but does not exist in recovery mode: support.apple.com/de-de/guide/remote-desktop/apdd0c5a2d5/mac
    – JoochenC
    Commented Feb 12, 2022 at 7:44

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