Open Terminal.app

At the command prompt type

strings /System/Library/PrivateFrameworks/NetworkConfig.framework/Versions/A/Resources/NetCfgTool

The listing of human readable code fragments includes:

"No user serviceable parts included."

This is classic old school, dry, Unix wit.

I found this whilst searching for the reason for MacOS-X NAT to default to 192.168.2.1, and/or how to change it ...