What is the difference between IDS and IPS?

Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) are both crucial components of network security, but they serve different purposes and operate in distinct ways. Here’s a breakdown of their differences:

Intrusion Detection System (IDS)

• Purpose: IDS is designed to monitor network traffic and identify suspicious activities or known threats.
• Functionality: It analyzes traffic patterns and compares them against a database of known attack signatures or anomalous behavior.
• Response: IDS is a passive system; it generates alerts when it detects potential threats but does not take action to block or mitigate them.
• Placement: Typically placed at strategic points within the network to monitor traffic to and from all devices.
• Types: Includes Network-based IDS (NIDS) and Host-based IDS (HIDS).

Intrusion Prevention System (IPS)

• Purpose: IPS not only detects but also prevents identified threats from causing harm.
• Functionality: It actively monitors network traffic and can take immediate action, such as blocking malicious traffic or resetting connections.
• Response: IPS is an active system; it can automatically respond to threats in real-time to prevent attacks from succeeding.
• Placement: Often placed in-line with network traffic, meaning all data must pass through the IPS for inspection.
• Types: Includes Network-based IPS (NIPS) and Host-based IPS (HIPS).

Key Differences

• Action: IDS alerts administrators to potential threats, while IPS takes proactive measures to block or mitigate threats.
• Positioning: IDS is typically deployed out-of-band (monitoring traffic without being in the direct path), whereas IPS is deployed in-line (directly in the path of network traffic).
• Response Time: IDS relies on manual intervention after an alert, while IPS can automatically respond to threats in real-time.