network mtr I just want to introduce you to nice little network diagnostic tool which combines ping and traceroute it does a traceroute and then repeatedly pings all the nodes along the route. use like this mtr 8.8.8.8
software ipcalc A collegue of mine just recently told me about ipcalc, It's a little but usefull subnet calculator. Before ipcalc I used to do subnet calculations the analogue way (pen & paper) but this is just so much easier and its in color. Check it out :)