There is a caveat. On some machines, IPv6 may be the default IP version to use by codice_2. Thus, the host specified by the hostname is contacted using IPv6, and the user might not know about this. Ports may appear closed in the test, even though they would be open when using IPv4. This can be difficult to notice and may cause the false impression that the port is blocked, while it is actually open. You can force the use of IPv4 by using adding codice_3 to the options of the codice_4 commands.