IP over Thunderbolt for M1 TB/USB4

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Level 1

10 points

IP over Thunderbolt for M1 TB/USB4

For Thunderbolt 3 Macs, a simple TB3 direct connection provides IP over thunderbolt: https://support.apple.com/guide/mac-help/ip-thunderbolt-connect-mac-computers-mchld53dd2f5/mac

Is it reasonable to expect that making the same 'direct' connection, only this time via the M1 TB4 port to an approved TB4 Hub in the middle would work in the same way?

Scenario 1: connect mac mini 2018 to M1 mac via TB3 cable; result IP over Thunderbolt connection successful

Scenario 2: connect M1 mini to Thunderbolt 4 hub, then to 2018 mini with the TB3 cables (using the TB4 cable for hub to M1) is not successful

Seems to me that something is wrong with Hub (more likely) or with the Big Sur support for TB/USB4 Hubs; thought I saw a lot of bragging about how wonderful TB/USB4 Hubs would be with M1 TB4, not loss of basic thunderbolt function

Thoughts?

Mac mini, macOS 11.2

Posted on Mar 1, 2021 2:40 PM

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Answer 1

Halliday

Level 4

2,677 points

Mar 3, 2021 7:09 PM in response to littlefooch

Welcome, littlefooch, to Apple Support Communities!

The most likely issues are the distinction between USB4 vs. USB-C/Thunderbolt-3 ports; the compatibility of the hub with USB4 carrying the appropriate protocols; and cable compatibility (there are at least three levels of cable compatibility).

You already know that a direct cable will work.

Hence. If the both cables connected to the hub work, each separately, then any failing is the hub.

With your «Windows 10 20H2» setup, what hardware did you use, with what sort of ports?

Incidentally, I’m not at all surprised that a claimed «Thunderbolt 4 hub» doesn’t work in your planned configuration. (Is that Intel’s label for a USB4 with Thunderbolt-3 support? [Never-mind. I’ve already verified that.])

It may work with USB4 devices, but may not work with USB-C/Thunderbolt-3 devices.

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Answer 2

littlefooch Author

Level 1

10 points

Mar 4, 2021 3:02 PM in response to Halliday

Hello Halliday and thanks for your reply and info.

As I mentioned, connecting the hub upstream port to the M1 mini, then a tb3 downstream port directly to a 2018 mini tb port does not work with IP over thunderbolt (intermittent connection that then fails)

Interesting, if the hub upstream is connected to the 2018 mini, and then a tb3 cable connects a downstream hub port one of the tb ports on the M1, IP over thunderbolt DOES work.

I send more info soon about the Win 20H2 connections using the hub.

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Answer 3

littlefooch Author

Level 1

10 points

Mar 3, 2021 6:31 PM in response to littlefooch

Looks like no interest in this topic.

Final thought - IP over Thunderbolt via the USB4 doc works in Windows 10 20H2 (but apparently not Big Sur)

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Answer 4

Halliday

Level 4

2,677 points

Mar 8, 2021 10:11 PM in response to littlefooch

This alternate configuration, littlefooch, looks like it may work by setting the hub into a backward compatibility mode, so, instead of working strictly as a USB4 (Thunderbolt-4) hub, it goes into a mode compatible with USB-C/Thunderbolt-3, or some such.

Just an educated guess, though.

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IP over Thunderbolt for M1 TB/USB4

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