macOS 15 (Sequoia) has new network privacy settings that might display repeating pop-up windows. This article shows how to disable the feature that is responsible.
Overview
macOS Sequoia introduced a feature for Wi-Fi connections that provides a rotating, private address, making your computer more difficult to attack. However, on an organizational network this can cause the system to pop up messages that the computer's name is already in use. The computer using the name is your computer, of course, but under its previous address. We can turn off the network address randomization to make the message go away.
Steps
Only take these steps for known networks:
- Eduroam on campus
- Home network
If you are traveling and on a public network, keep the address randomization on for that connection.
Go to Network Settings
- Go to System Settings > Network or the Wi-Fi > Wi-Fi Settings item in the top menu.
- Select the Details button for the active network.
- Under Private Wi-Fi Address, select Fixed, then OK.
This will stop randomizing the address. Repeat for any other organizational (not public) network you are experiencing the issue with.