Intrusion Prevention System

woman at locked computer screen

In a world of growing cybersecurity threats, having a robust intrusion prevention system in place is more important than ever before. 

Table of Contents

What is an Intrusion Prevention System?

Intrusion prevention is the intervention against unwanted or unauthorized access to your network. An intrusion prevention system monitors and manages network traffic to ensure that your network devices are being used the way they are intended. 

An intrusion prevention system is the second line of defense after your firewall. Intrusion prevention systems free up your IT staff or your managed service provider from having to manually monitor and manage all network traffic. 

Intrusion Prevention vs. Intrusion Detection

Intrusion detection and prevention systems are related, but different. Intrusion detection systems are passive devices that sit parallel to your network, observing traffic as it passes and sending out alerts as necessary. These systems are designed to tell you when a threat is already in your network and report on its behavior.

Intrusion prevention systems, on the other hand, sit in line with your network. In addition to tracking network traffic, they analyze and filter that traffic. This ensures no hostile traffic makes it to your internal networks. 

Both intrusion detection and prevention techniques differ from firewalls in that firewalls only monitor traffic between your network and other networks. As such firewalls cannot identify internal threats.   

Furthermore, they differ from anti-malware software in that they detect unusual network activity, in addition to recognizing known threats. This gives intrusion detection and prevention systems a broader scope of security. 

Intrusion detection and prevention software and hardware comes from a variety of vendors. Larger brands often don’t have the support services available for all of their clients. Smaller vendors, while providing more attentive customer service, often have subpar products. Finding the balance between support and service is tricky. 

Benefits of an Intrusion Prevention System

Advantages and disadvantages vary depending on what tools you use. The most common benefits are: 

  • Incident reduction: The primary benefit of an intrusion prevention system is a reduction in network security incidents. Through automated threat mitigation, the intrusion prevention system will filter out most security threats. 
  • Selective logging: Because a lot of sensitive data often goes through business networks, intrusion prevention systems can selectively log only security concerns to maximize data efficiency. 
  • Privacy protection: Many intrusion prevention systems can keep communications private by assessing only the metadata for evidence of malicious network activity. 
  • Password protection: Protect against brute force password attempts. By detecting unusual and persistent traffic, an intrusion protection system can stop password cracking in its tracks. 
  • Zero-day prevention: Because an intrusion prevention system detects unusual network activity, rather than known threats, it can find and protect vulnerabilities in advance of them becoming known. 
  • Availability assurance: An intrusion prevention system can stop malicious traffic and ensure normal operations in a DoS or DDoS attack. 

There are of course many other benefits as well. While some systems have disadvantages compared to others, all of them are superior to having no preventative solutions at all. 

man in front of cyber lock

Types of Intrusion Prevention Solutions

Intrusion prevention systems typically consist of two types of prevention:  software and hardware. While each can individually improve your security posture, using both in tandem greatly increases your network security. 

Intrusion prevention software is the interface between your security team and the devices they monitor. The intrusion prevention software monitors your network traffic and generates alerts or automatically blocks traffic based on its configuration. 

There are a number of ways to deal with network traffic and network traffic abnormalities. For this reason, it’s often best to have an expert configure your software. 

Intrusion prevention devices or intrusion prevention appliances are pieces of network equipment you plug directly into your network. Similar to the software, intrusion detection hardware monitors network traffic for abnormalities and responds according to a predetermined set of rules. 

Intrusion prevention software has somewhat of a leg up on the hardware in that it can be updated. Thus if there are new kinds of threats, intrusion prevention hardware won’t be able to adjust to them. 

Because of this, it’s recommended to back up your intrusion prevention hardware with intrusion prevention software. This is also why it’s important to keep your intrusion prevention software up to date. 

Intrusion Prevention System Best Practices

Although the needs of every business are different, there are some best practices for setting up an intrusion prevention system. While these best practices will tell you what you need to do, they do not explain how to do it. That’s because the needs of every network are unique. 

  • Profile normal network activity: Because intrusion prevention systems operate on the basis of detecting abnormal traffic, you need to get a good baseline. Make sure you set up your intrusion prevention system at a time when you don’t expect unusual surges or dips in traffic. You may want to get multiple readings throughout the day to see how network traffic changes over the day. 
  • Deploy behind a firewall at the edge of your network: To ease the burden on your intrusion prevention system, a firewall protects against unauthorized traffic coming into the network. This enhances your intrusion prevention system’s ability to maintain normal traffic levels. 
  • Install multiple systems to cover intra-host traffic: Because not all threats are external, installing intra-network intrusion prevention devices or software is a valuable part of your security profile. This protects against threats resulting from things such as phishing attacks. 
  • Calibrate your installations: Based on your normal network traffic, you need to fine tune the amount of traffic allowed without signaling a security event. You want it to be high enough not to generate false positives but not too high that threats go undetected. 

How you do this is a matter of discretion and relies on a degree of experience to get correct. There are a lot of ways to configure an intrusion prevention system. Doing so correctly usually requires a degree of expertise the average computer user doesn’t possess. 

Foresite’s Intrusion Prevention Solutions

Foresite has installed and managed intrusion prevention systems for over 300 clients. Our proprietary ProVision security platform can be adopted to complement your existing security infrastructure or as a standalone SEIM software. 

ProVision monitors network traffic, generates alerts, and takes action according to a predefined set of rules. ProVision handles event logging, correlation, analysis, and reporting of security incidents. Our managed detection and response (MDR) identifies, detects, and automatically remediates threats. 

In addition to our software offerings, Foresite offers cybersecurity assessments and consulting solutions. We offer vulnerability assessments such as penetration testing and web application testing. We also operate a 24/7 on-shore security operations center (SOC) to address security incidents as they happen. 

With clients in the US, UK, and beyond, Foresite is a trusted solution for all of your security needs. We provide SOC, SIEM, patch management, asset management, and MDR services. Our certified cybersecurity experts will keep your networks running smoothly and securely. 

For more information about how we can assist you with the deployment of an intrusion prevention system, contact us today. 


Tristin Zeman

Tristin Zeman is the Digital Marketing Manager at Foresite. For the past 10 years, she has helped organizations of all sizes create and scale marketing programs through digital and traditional marketing channels and efficient marketing operations.

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