Clicking on the genlist menu item in Backtrack Linux opens a terminal window and outputs the genlist help menu at the top. Genlist is a Perl script written to provide an easy way to generate a list of live hosts on a network or set of networks so you can then begin analyzing those hosts. All the genlist Perl script does is call nmap with the -sP switch and parse the results so only the live IP addresses are output and as simple as it seems its a handy little tool if you do penetration testing on a regular basis. Below we describe genlist in more detail and show an example of genlist in action.
A tool that is more than likely not used very often in Backtrack is the ipcalc which is a command line to that will quickly provide you broadcast address, network address, netmask, and Cisco wildcard mask. If you do a lot of Backtrack Linux installations that each require different IP information for various networks this tool can be really useful to verify settings made in the networks file in Ubuntu/Backtrack. I used to find myself breaking out a iPhone IP calculator on a regular basis and while I still do use that application I prefer ipcalc from the command line if its readily available. Below are details regarding ipcalc and the various switches available to it.