Have you heard of intrusion detection systems? Also known as IDS, this software is often used to detect any violations that might cause danger to the network. This software is kind of like a firewall, but it has additional features that can help to guard networks against attacks.

Here are some free IDS software options that you might want to consider:

Bro IDS

This software is often used along with Snort, and it logs everything that it sees so that you can go back and take a look at network activity. Bro IDS is very useful for people who want to take a look at traffic analysis, and it is used by a number of organizations including major universities, research labs, scientific labs, and in supercomputer labs. All of these use Bro IDS to keep their systems secure. Additionally, this software is part of the Software Freedom Conservancy.

Prelude OSS

If you have ever used or heard of Prelude Siem, you will probably want to take a look at Prelude OSS, which is an open source version of Siem. This software is a type of hybrid system for detection that has been fully designed to be extremely fast, solid, and widely distributed. It is perfect for training exercises, and it is widely used in research organizations and in smaller IT departments. Though Prelude OSS was not created for critical or large networks, it is a great option for those looking for a limited IDS or looking to learn more about Prelude Siem before they buy it.

Snort for Windows

This software is open source, and it can do things like search content, protocol analysis, and detect probes and/or attacks. This software also does SMB probing, stealth port scans, CGI attacks, buffer overflows, and more.

Suricata

This, too, is open source, and it is often compared to Snort…but it’s better. Suricata does things like network monitoring and intrusion prevention and detection. This software is available for Windows, Mac, Linux, and other platforms, too. The software is free, but developer training is held throughout the year, and there are fees associated with that.

Malware Defender

This is a free Windows-based program that has network protection features. The software offers intrusion prevention along with malware detection. You might use this program at home, as it is good at picking up malware, but the intrusion prevention features are a bit more complex. Malware Defender used to be a commercial software, but these days, it works as an HIPS, or host intrusion prevention system, and monitors a single device for any activity that looks suspicious.