This work dates from 2016 when I had the latest version of IWL's TCP/IP Test Suite. I wanted to explore the Test Suite’s capabilities and ran it against various TCP/IP stack implementations.

Here are the results from a vintage 2016 release of FreeBSD 10. Note that while vintage, this code is found in many embedded systems. FreeBSD Test Results

Newer versions of the TCP/IP Test Suite have more extensive tests.