OS X Mountain Lion: Investigate your network connections

Network Utility combines several information and troubleshooting tools you may find helpful if you understand basic networking. You may be asked to use Network Utility to check your network if you contact Apple Support.

Using Network Utility, you can check your computer’s network interfaces, test access to specific hosts or IP addresses (ping), review network performance statistics, convert between IP addresses and host names, find user information, and scan active TCP ports.

Help for some of these tools is available in Terminal. Type “man” followed by the tool’s name (for example, “man ping”).