Estimates show that up to 800-900 million people depend on IPv4 for their daily communications needs. Since the inception of the Internet, IPv4 has assumed an unprecedented importance in the global scale. IPv4 implementations are found in almost all modern computer systems. This includes routers, switches, firewalls, desktop and server systems, laptops, PDAs, cell phones and other mobile systems, as well as a large number of various embedded systems. All of these devices are vulnerable to exploitation through externally-supplied malformed protocol data. Effects of malicious data range from transient parsing errors to complete system takeovers. ICMPv4 as part of IPv4 protocol stack has an extremely crucial role in modern society, the dependability and reliability of ICMPv4 implementations must be verified. ICMPv4 implementations are often tightly coupled with the underlying operating system, which means that serious flaws in ICMPv4 protocol handling may easily result in total system compromises. ICMPv4 Test Tools help prevent this by making ICMPv4 implementations more robust. ICMPv4 test suite implements a large variant of tested ICMPv4 messages. Some of the test groups are for testing ICMPv4 Request messages, these groups expect a response from SUT. ICMPv4 Control message groups are for testing Control messages, these groups do not except a response for SUT. In addition suite contains test groups for Response messages. Regular Response groups expect a request from SUT before response is sent, while Unsolicited Response message groups do not expect a request. The list of supported message types are shown below in the "Tested ICMPv4 Messages" table.