Since I’m occasionally asked these things, here’s how to find some commonly needed network information in various operating systems – for now, Windows, Mac OS X and Linux, as well as Android and iOS (iPhone/iPad/etc.). My assumption is that the people running BSD, Solaris, etc. (and yes, all of those have visited my blog) know this stuff. I won’t go into descriptions of what these “strange” things are.

First off, I know that most desktop computer users are used to doing everything graphically. If you know what you want to do, the command line is a lot faster. There’s no reason to fear it. Watching a cooking show might be wonderful if you have no idea how to cook a meal, but it’s not very efficient if you just need the list of ingredients.

First off, how to get a command prompt:

• Windows: For XP and before, Start -> Run -> type “cmd”, click Ok. For Vista, Start -> type “cmd”, click it.
• Mac OS X:Applications -> Utilities -> Terminal
• Linux/Unix: Konsole, Xterm, whatever else you use, or just drop to command line/runlevel 3

In the following examples, anything in monospace font should be typed exactly as is at the command prompt. Note: some of this may need to be run as Administrator/root. If you’re using Windows Vista or newer, once “cmd” appears under Programs, right-click it and select Run as Administrator. On Mac or Linux, you may have to run as sudo, and you may have to specify an absolute (full) path.

Default Gateway – on a simple home network, this is the IP address of your router.

• Windows: route PRINT, look for the line beginning with “Default Gateway:”
• Mac OS X: route get default, look for the “gateway:” line.
• Linux: sudo /sbin/route, look for the line beginning with “default”, it will be the in the “Gateway” column. If your system uses iproute2, ip route show.

MAC Address – The (more or less) globally unique address of your computer’s network adapter. Each network adapter (wired, wireless, etc.) has its own. Looks like xx-xx-xx-xx-xx-xx or xx:xx:xx:xx:xx:xx or xxxxxx:xxxxxx where each “x” is a number from 0 to 9 or a letter from a to f.

• Windows: ipconfig /all, look for the name of your network connection and then the indented line starting with “Physical Address”.
• Mac OS X: ifconfig, look for your network adapter (en0 is wired ethernet, en1 is your AirPort), the address will be on a line after “ether”.
• Linux: ifconfig, look for “HWaddr” for the right interface.

WAN (Internet or External) IP Address) – Go to whatismyip.jasonantman.com.

Ping another host – A ping test shows (simple explanation) how long it takes packets to get from your computer to another. (For you Warcraft players, this isn’t the same as the ping times shown in-game, and you can’t ping the realm servers).

• Windows: ping -t IPaddress, the -t makes it run until you type Control-C to stop it.
• Everything else: ping IPaddressCtrl-C (or whatever your OS uses) to stop it.

I’ll update this with more when I get time…