Regression testing is one of the most critical elements of the test artifacts and proves to be one of the most preventive measures for testing a software. Currently, within FreeBSD, there is no such tool to perform regression testing of the TCP/IP network stack. The purpose of this project is to develop tests using a regression testing tool which can then be integrated with FreeBSD. The wire level regression test suite will exercise various states in the TCP/IP protocol suite, with both IPv4 and IPv6 support. Once integrated, the tool will also facilitate further development of such tests. The regression testing tool of choice here is Packetdrill. Packetdrill currently supports testing multiple scenarios for TCP/IP protocol suite within Linux. The existing Linux test suite implemented within Packetdrill will provide a basis for understanding, and implementation of the FreeBSD test suite.