IP address over ethernet is self-assigned when using a gigabit adapter
Hi,
I'm using a MacBook Air, M2, running Sonoma 14.1.2.
It connects OK to the internet over Wi-Fi but cannot connect over ethernet when using a gigabit adapter in an outbuilding in the garden.
This is the situation:
The garden is small, and we have an office there, but the wi-fi is unreliable as the office has thick walls; therefore, I need to be able to use the ethernet connection we have from the living room in the house to the office.
Scenarios:
- Macbook can connect on wi-fi everywhere in the house and office (but unreliably in the office).
- Macbook can connect on ethernet in the living room, straight from the router, using a Belkin USB-C LAN adapter.
- Macbook cannot connect on ethernet in the office, using same Belkin USB-C LAN adapter. It gets a self-assigned IP address, or a green light, but no data comes through.
- Husband's iMac can connect on ethernet in the office. His iMac doesn't need an adapter, it has an ethernet port.
- Husband's iMac cannot connect on ethernet in the office if ethernet cable is coming out of a TP-Link TL-SG1005D, 5 Port Gigabit Ethernet Network Switch.
Troubleshooting (none of this solved the problem, apart from number 4 temporarily)
- Re-started router, laptop.
- Contacted my internet provider to check there were no issues with our line.
- Started Macbook on safe mode.
- Created new user in Macbook with admin rights and connected succesfully in the office. This happened only once and hasn't happened again.
- Re-installed previous operating system MacOS Ventura after using repair utility.
- Upgraded to Sonoma.
- Renewed DHCP lease.
- Added DNS servers: 8.8.8.8, 8.8.4.4, 1.1.1.1, 9.9.9.9
Summary: MacBook air would only connect to the internet if straight from the router (with the Belkin adapter, as it does not have an ethernet port). If I need to add another step to this physical connection (through the CAT5e socket at the wall in the office, or the TP-Link switch) it self-assigns an address. This is the case for husband's iMac too, it would only work if there are no extra physical steps in the office, i.e. not through the TP-Link switch.
I have tried everything I can think of, and I have read many threads with no solution.
If anyone can crack this horrible puzzle, I would be SO grateful. Thanks!
MacBook Air, macOS 14.1