Ethernet Goes On / Off like cable being unplugged / plugged in.

[M0001]

Any suggestions on where to start with why Ethernet goes on / off?

... it was working, I swapped some non-boot drives out, rebooted and it cycles on the ethernet now.

It starts cycling once the kext loads.

If I boot into some other OS it works.

[MaLd0n]

extract one dump

RunMe.app

[M0001]

The status will go between:

"The Cable for Ethernet is connected but your computer does not have an IP address"

or

"Either the cable for the Ethernet is not plugged in or the device at the other end is not responding"

BIOS settings of "Wake on LAN" either disabled/enabled matter not.

Send me ICBM-20.zip

[MaLd0n]

[ref]M0001[/ref], try delete files in this folder, delete connection too, reboot and create again

[M0001]

Same result, except the computer name changed .. (of course)

Send me iMac-Pro.zip

[MaLd0n]

[ref]M0001[/ref], take one shot, try without DSDT

after test without DSDT use it

DSDT.aml.zip

[M0001]

No change when I removed DSDT.aml from ACPI/Patched.

Replaced it with the one provided above, still the same.

I also plugged in a Belkin USB-C ethernet dongle. I don't get the "bouncing", I can set an IP manually but it still does not work.

Added in 4 minutes 49 seconds:

Without the interface defined, if I plug in the cable, the link remains solid.

As soon as I add en0 and apply it, the link status starts cycling between cable is plugged in, self assigned IP, cable is unplugged, repeat.

It does the same thing with both ports, and acts similarly with USB ethernet.

[MaLd0n]

[ref]M0001[/ref], is a very strange

[john191011]

Try setting the link fixed to e.g. 100 fdx.

[erroruser]

try this go to /Library/Preferences/SystemConfiguration/ an delete NetworkInterfaces.plist then empty trash repair permissions an reboot hope this help you