The bridgeO is the Thunderbolt bridge that bridge together the various Thunderbolt 3 adapters in your mac (in my MacBook Pro 2018, there's 4 of them, all members of bridge0).

Ethernet is a buit-in feature of thunderbolt 3.

To bring this bridge active, you need to bring a thunderbolt Ethernet interface up, so connect a device that use this feature.

Note: the standard Apple Ethernet adapter is really a USB-C to Ethernet adapter, not thunderbolt, and doesn't bring up the thunderbolt interface. (it creates a separate interface)

If you really want to bring the bridge up (why?), you can probably add another interface to the bridge (like the usb-c to Ethernet adapter) and connect this interface. You can give it a shot using the brctl command.

The bridge0 is the Thunderbolt bridge that bridges together the various Thunderbolt 3 adapters in your Mac (in my MacBook Pro 2018, there's 4 of them, all members of bridge0).

Ethernet is a buit-in feature of thunderbolt 3.

To bring this bridge active, you need to bring a Thunderbolt Ethernet interface up, so connect a device that use this feature.

Note: the standard Apple Ethernet adapter is really a USB-C to Ethernet adapter, not Thunderbolt, and doesn't bring up the Thunderbolt interface (it creates a separate interface).

If you really want to bring the bridge up (why?), you can probably add another interface to the bridge (like the USB-C to Ethernet adapter) and connect this interface. You can give it a shot using the brctl command.

The bridgeO is the Thunderbolt bridge that bridge together the various Thunderbolt 3 adapters in your mac (in my MacBook Pro 2018, there's 4 of them, all members of bridge0).

Ethernet is a buit-in feature of thunderbolt 3.

To bring this bridge active, you need to bring a thunderbolt Ethernet interface up, so connect a device that use this feature.

Note: the standard Apple Ethernet adapter is really a USB-C to Ethernet adapter, not thunderbolt, and doesn't bring up the thunderbolt interface.

The bridgeO is the Thunderbolt bridge that bridge together the various Thunderbolt 3 adapters in your mac (in my MacBook Pro 2018, there's 4 of them, all members of bridge0).

Ethernet is a buit-in feature of thunderbolt 3.

To bring this bridge active, you need to bring a thunderbolt Ethernet interface up, so connect a device that use this feature.

Note: the standard Apple Ethernet adapter is really a USB-C to Ethernet adapter, not thunderbolt, and doesn't bring up the thunderbolt interface. (it creates a separate interface)

If you really want to bring the bridge up (why?), you can probably add another interface to the bridge (like the usb-c to Ethernet adapter) and connect this interface. You can give it a shot using the brctl command.