Intrusion detection systems (IDS) are a type of security technology that can help protect against cyber attacks by monitoring network traffic and identifying potential security breaches.

Here are the basic steps of how IDS work:

1. IDSs are typically deployed on the network and can monitor traffic from multiple sources, such as network devices and servers.
2. The IDS uses a set of rules or signatures to identify suspicious or malicious traffic. These rules are based on known attack patterns and can be updated as new threats are discovered.
3. When the IDS detects suspicious or malicious traffic, it will generate an alert to notify the security administrator of the potential security breach.
4. Based on the alert the administrator can choose to take action such as:
   • Investigating the alert to determine the cause of the intrusion and taking steps to prevent it from happening again.
   • Taking measures to stop or mitigate the intrusion.
   • Documenting the incident for compliance purposes
5. IDSs can be configured to operate in one of two modes:

• Signature-based IDS: look for specific patterns in network traffic that are known to be associated with malicious activity
• Anomaly-based IDS: monitor network traffic for any unusual or abnormal activity that might indicate an intrusion

It’s important to note that IDSs are detection systems and are not able to prevent attacks, their main function is to detect an attack, it’s just an alerting mechanism, as an incident response approach is needed. With an IDS, an organization would be able to detect an intrusion more quickly, but there would still be a need for a response to the intrusion.