Many network tools, including an internet/network port scanner, which can scan any class A, B or C network for any list of open ports, and takes advantage of multi-threading. You can also save all lists to a text file. Windows graphical ping utility allows you to change the size of the packets, the timeout, and the number of packets to ping. Windows graphical DNS Utility shows you extended information on a given hostname or IP address. Windows graphical utility for connecting to an open port and testing commands. Works like a telnet client but you can send 1 line at a time. Windows graphical Whois client where you can configure the whois server for multiple DNS name types.