Snort is an open-source network intrusion detection system (NIDS) and intrusion prevention system (IPS) developed by Sourcefire. It is capable of performing real-time traffic analysis and packet logging on IP networks. Snort can detect a variety of attacks and probes, such as buffer overflows, stealth port scans, CGI attacks, SMB probes, and much more.
To install Snort on a Linux server, follow these steps:
Update your package list:
sudo apt-get update
Install Snort:
sudo apt-get install snort
Configure Snort:
Edit the Snort configuration file located at /etc/snort/snort.conf to suit your network environment.
Start Snort:
sudo systemctl start snort
Snort’s configuration file is typically located at /etc/snort/snort.conf. This file contains various settings that control how Snort operates. Key sections include:
Snort uses a rule-based language to define the traffic it should monitor and the actions it should take. Rules are typically stored in the /etc/snort/rules directory. A basic rule looks like this:
alert tcp any any -> 192.168.1.0/24 80 (msg:"Possible web attack"; sid:1000001;)
This rule generates an alert for any TCP traffic destined for port 80 on the 192.168.1.0/24 network.