Tracking Down Unnecessary Servers
To keep your system running securely and efficiently, you should periodically audit your system, looking for servers that need not be running. Here’s how to do it.
Tuesday, March 15th, 2005
Linux is an extremely flexible operating system. You can run it on a server, on a workstation, or in various more specialized roles. This flexibility also means that you can’t be sure just what you’ll get when you install Linux — at least, not without substantial experience with a specific distribution. Perhaps the distribution you install runs certain server programs by default. And even if you know the default installed configuration, your system can change over time. For example, you might have tried out a server program, decided you didn’t want it, and then deleted it. Or perhaps just forgot about it.
For whatever reason, unnecessary servers often run on and on. Some can be a nuisance, consuming CPU time, memory, network bandwidth, and other resources that you’d rather devote to other tasks. Worse, unnecessary servers can be a security threat. A bug or misconfiguration in a server can leave your system vulnerable to attack. This threat is particularly great when you’re unaware that the server is running, because you’re unlikely to spend time upgrading such servers and tending to configurations.
For these reasons, you should periodically audit your system, looking for servers that need not be running. Once you’ve identified such servers, you should delete them or at least disable them.
Using netstat to Find Running Servers
