Netplug is a Linux daemon that manages network interfaces in response to network cables being plugged in and out. If you're familiar with Windows XP, which just does the Right Thing when you plug an ethernet cable into a laptop, netplug will need no further explanation. Basically, netplug brings up an interface and runs a DHCP client when a cable is plugged into that interface, and it brings the interface down when the cable is unplugged. On a typical Linux system or laptop, you have to run a command (such as "/sbin/ifup") manually to handle these events, but netplug automates this for you.
