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Thunderbolt Ethernet not working macOS Catalina

Status: Connected


Shows an amber dot next to the Thunderbolt Ethernet


"Thunderbolt Ethernet has a self-assigned IP address and will not be able to connect to the internet.


Have gone too TCP/IP > (using DHCP) > Renew DHCP Lease. Shows IPv4 Address + Subnet Mask. (not Router)


any idea thanks


iMac 21.5", macOS 10.15

Posted on Dec 22, 2019 10:23 AM

Reply
4 replies

Dec 22, 2019 2:37 PM in response to Jaydonny

This is the Thunderbolt to Gigabit Ethernet adapter you are working with yes?

What is it being connected to? (Switch? Cable modem? Another computer?)

If it is a switch, are you sure there are no VLANs configured on the network? Or, inversely, are there any vlan interfaces on your Mac that uses the thunderbolt ethernet as its physical port?

Is it possible to manually assign a valid address for the network you are trying to connect to? That might let you connect (unless something like 802.1x is involved) and help troubleshoot.

Thunderbolt Ethernet not working macOS Catalina

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