What are IDS and IPS in Network Security?

Intrusion detection systems (IDS) and intrusion prevention systems (IPS) are essential to protect against cyberattacks. You will need both because an IDS detects threats and notifies the system admins, and an IPS actively stops the attack in real time.

In this article, we will explain the meaning of IPS and IDS in cyber security, understand how each of them works, and list out some popular IDS and IPS tools. We will also compare both of them to find the similarities and differences between them.

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What are IDS and IPS in Network Security?

IDS and IPS are two important technologies that are used to detect and stop cyber threats. IDS stands for Intrusion Detection System, and IPS stands for Intrusion Prevention System.

Let's look at their definition, advantages, and disadvantages to fully grasp their purpose.

What is an Intrusion Detection System? 

An Intrusion Detection System (IDS) monitors network events and analyzes them to identify potential security incidents and cyber threats. They act as a vigilant observer and notify you when suspicious activities occur.

Now IDS's main job is to detect and notify only, so it will be your responsibility to resolve the incidents.

Read our article on What is Incident Response?

Types of IDS

There are two types of IDS solutions:

1. Host-Based IDS (HIDS): Operates at the endpoint level, protecting individual devices by monitoring local activities such as file changes, system logs, and running processes. 

2. Network-Based IDS (NIDS): Monitors the traffic across an entire network, analyzing data packets to detect anomalies or malicious activities.

How Does IDS Detect Intrusion?

An intrusion detection system uses 3 methods to identify the cyber threat: 

1. Signature-Based Detection: IDS will match observed network behavior against a database of known threat signatures, and if it detects similar activity, it will notify the admins. While this method is fast and precise, it cannot detect unknown or zero-day threats. 

2. Anomaly-Based Detection: IDS establishes a baseline of normal network behavior and flags any deviations as potential threats. This approach can identify possible attacks but can also raise false alarms. 

3. Hybrid Detection: Combines signature-based and anomaly-based methods for enhanced accuracy and speed in identifying threats.

Advantages of Intrusion Detection System

● Provides detailed monitoring and logging of network activity. 

● Operates passively without affecting network performance. 

● Suitable for diverse network environments and configurations. 

● Lower deployment and maintenance costs compared to IPS. 

Disadvantages of Intrusion Detection Systems

● Relies on manual intervention to address threats. 

● Can generate inaccurate alerts, requiring further analysis. 

● Detects but does not prevent or mitigate threats. 

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What is an Intrusion Prevention System? 

An Intrusion Prevention System (IPS) is a network security technology that detects and stops any possible attack in real time. It is placed between internal and external networks, where it can monitor, analyze, and take action to block malicious activities. 

Types of IPS

There are three types of intrusion detection systems:

1. Host-Based IPS (HIPS): Protects individual devices by monitoring and mitigating threats at the host level. 

2. Network-Based IPS (NIPS): Protects entire networks by monitoring and controlling traffic at critical junctions. 

3. Wireless IPS (WIPS): Detects and prevents unauthorized wireless access points. 

Advantages of Intrusion Prevention System

● Automatically blocks threats in real-time. 

● Combines detection and prevention for robust security. 

● Reduces response time and workload for security teams. 

● Adapts to high-speed networks and large-scale deployments. 

Disadvantages of Intrusion Prevention System

● Inline deployment may introduce delays in traffic processing. 

● Requires careful tuning to avoid disruptions. 

● Typically involves higher upfront and operational expenses. 

● Misconfigured policies can inadvertently block legitimate traffic. 

How are IDS and IPS Similar?

Both IDS and IPS are network security tools and they monitor network traffic for malicious activity. Some similarities between IDS and IPS are: 

1. Both systems aim to protect networks by identifying and addressing security threats. 

2. Both rely on signature-based and anomaly-based techniques for identifying malicious activities. 

3. Utilize automation to reduce the burden on security teams, enabling swift responses to threats. 

4. Facilitate adherence to data protection regulations by monitoring and securing enterprise networks. 

5. Support the enforcement of enterprise security policies, such as restricting unauthorized VPNs or blocking malicious domains. 

Difference Between IDS and IPS 

Why You Should Use IDS and IPS Together

IDS and IPS are great security tools individually, but together they enhance your cyber defence to the next level. Every big organization combines IDS and IPS solutions for maximum security.

Here are some reasons why you should also use both IDS and IPS for your network security:

1. Layered Defense Strategy

Combining IDS and IPS creates a multi-layered security approach. IDS provides deep visibility and forensic insights, while IPS actively blocks threats. This layered setup ensures both detection and prevention, reducing the chances of successful attacks.

2. Improved Threat Intelligence

IDS can log and analyze suspicious patterns over time, helping to identify emerging threats. IPS can then use this intelligence to update its rules and proactively block similar attacks in the future, creating a feedback loop for smarter protection.

3. Minimized False Positives

IDS alerts can be reviewed before taking action, helping to fine-tune IPS rules. This collaboration reduces the risk of IPS blocking legitimate traffic, ensuring smoother operations without compromising security.

4. Real-Time Response with Context

While IPS acts instantly to block threats, IDS provides contextual data about the attack, such as origin, method, and target. This helps security teams respond more effectively and understand the bigger picture.

5. Security Logging for Forensics and Accountability

Using IDS and IPS together ensures that every security event is logged and traceable. IDS provides detailed records of suspicious activities, while IPS logs prevention actions. This comprehensive logging supports incident investigations, accountability, and helps organizations maintain transparency in their security operations.

Top 5 IDS and IPS Products

Here’s a concise version of the leading IDS and IPS solutions, each described in a single line: 

IDS Tools

1. Snort: Open-source network IDS for real-time traffic analysis and packet logging. 

2. Suricata: High-performance IDS/IPS with deep packet inspection and multi-threading. 

3. Zeek (formerly Bro): Advanced network IDS focused on application-level monitoring and file inspection. 

4. OSSEC: Host-based IDS for log analysis, file integrity checking, and rootkit detection. 

5. AIDE: Host-based IDS for monitoring unauthorized changes to files and directories. 

IPS Tools

1. Cisco NGIPS: Next-Generation IPS with deep packet inspection and advanced threat detection. 

2. Palo Alto Networks NGFW: Combines firewall and IPS functionalities with malware protection and threat prevention. 

3. Check Point Quantum IPS: High-performance IPS integrated with Check Point’s security architecture for real-time detection. 

4. Trellix (McAfee + FireEye): Combines McAfee’s endpoint protection and FireEye’s threat intelligence for advanced IPS capabilities. 

5. ZScaler Cloud IPS: Cloud-based IPS for real-time traffic inspection and threat prevention in distributed environments. 

Conclusion 

While IDS and IPS serve distinct purposes, they are complementary components of a robust cybersecurity strategy. IDS excels in detection and analysis, while IPS provides proactive threat prevention.

Together, they form a formidable defense against cyberattacks, ensuring the safety and integrity of organizational networks. By understanding their roles and following best practices, organizations can leverage these tools to fortify their security posture in an increasingly digital world.