Hi,
I see that in macOS 12 (running 12.1), there is a new setting in Network preferences pane:
System Preferences --> Network --> Ethernet --> Limit IP Address Tracking
Limit IP address tracking by hiding your IP address from known trackers in Mail and Safari.
What does it actually do?
I tried searching the web, but it seems like this quite new and nothing is written about this new feature.
Search for "iCloud Private Relay"
e.g. https://support.apple.com/en-gb/HT212614
Or specifically for Limit IP Address Tracking:
https://nerdschalk.com/hide-ip-address-on-iphone-how-to-use-limit-ip-address-tracking-feature-for-this/