STOP AND GO

If you need to manage a large number of computers and services, Nagios is an excellent option. Nagios monitors computers, network connections, and servers, displaying the current health state of a web interface with the colors green (okay), yellow (warning), and red (critical). It is a pity that the web interface is so unobtrusive. If everything is quiet on the network front, an administrator can easily close the browser window and overlook the Nagios warning messages in the general flood of email traffic. One day, I decided there must be a better way. Luckily, Nagios is very easy to adapt and extend. With a little scripting and some cheap electronic hardware, I built a simple traffic light that can sit on top of a switch, cabinet, or desk to show the current network status.