Using netstat to monitor a server

It is important to always keep a watchful eye on your dedicated server. Monitoring tools may be external, available through service providers, or internal, already included in your Linux distribution. One important internal monitoring tool is netstat.

Netstat can provide you with useful information about the ports that system services are using. For example, to display information about the services using port 80, type the following command:

netstat -ant | grep 80

The command by itself will show all of the instances running on every port, but you can limit the output to port 80 with grep. This is a quick way to see how many instances of port 80 (your web server) are actually running. If you want to count them, type this command:

netstat -ant | grep 80 | wc -l

Netstat has many other features that you can use to learn about your network ports and how they are being used. For complete documentation on netstat, type “man netstat” from the command line.