How To Choose Between IDS/IPS

The choice between IDS/IPS or both has significant implications for cybersecurity. It therefore has significant implications for a business. With that in mind, here is a quick guide to the three key questions you should ask when choosing between IDS/IPS.

Is IDS/IPS mandated by a compliance program?

At a high level, the answer to this question should be simple to determine. You can just check the rules of the relevant compliance program and see if IDS/IPS is mandated.

In the real world, however, the answer is likely to be more complicated. Many compliance programs specify what you need to achieve. They leave it up to each organization to decide how they want (or need) to achieve it.

This means that practically speaking, compliance requirements may strongly point to IDS/IPS without it actually being explicitly specified. Also, compliance requirements are generally updated periodically. This means that the bias towards IDS/IPS may change over time (and possibly even change back again).

What is your main goal?

All business decisions should be taken with an end goal in mind. In the context of IDS/IPS, you need to decide if your goal is to improve your reactivity or your proactivity.

For completeness, all businesses should mix reactivity with proactivity. This is because you can never be completely sure that you can stop all threats before they damage you. You therefore still need to maintain a strong reactive capability.

The key question therefore is “Do you need to boost your reactivity or your proactivity?”. If the answer is reactivity, then IDS is your better choice. If it’s proactivity, then IPS is your better choice.

What is your current security environment?

You can only make an informed decision on whether you need to boost your reactivity or your proactivity if you are clear on your current security environment. Here are the five key points you should consider.

Perception of risk

With IDS/IPS the two key risks are false negatives and false positives. False negatives are when threats manage to slip through the IDS/IPS monitoring. These must then be addressed by other security tools and/or human administrators. False positives are when benign traffic is identified as a threat. They are an issue with both IDS and IPS.

With IDS, however, a human administrator can prevent any defensive action from being started. This prevents unnecessary disruption to the business. With IPS, by contrast, defensive action will be started automatically. This means false positives will create business disruption until a human administrator stands down the defense.

With IDS there is the secondary risk of a slow response and with IPS there is the secondary risk of an inappropriate auto-response. Both of these risks can, however, be mitigated by ensuring there is appropriate human oversight.

Response capability

Organizations need to assess their security team’s capability to respond promptly to alerts. An IDS primarily focuses on detection and alerting, requiring a more manual and proactive response from the security team. In contrast, an IPS offers immediate, automated responses, providing real-time mitigation against threats.

Understanding the organization’s response capability is essential for optimizing the effectiveness of the chosen security solution and ensuring a timely and effective reaction to potential security incidents.

Network architecture

Networks with limited resources might lean towards IDS as it monitors traffic without directly blocking it. This means that it does not impact processing speed.

By contrast, more complex networks might benefit from IPS or a combination of IDS and IPS. Using IPS on its own could buy human administrators more time to deal with the more challenging incidents that could take place in more complicated networks.

In the real world, however, complicated networks will almost certainly be segmented into zones. This would allow for the use of both IDS and IPS. IDS can monitor specific zones, providing detailed insights, while IPS can actively protect critical segments.

Integration with existing security infrastructure

Assess whether the IDS or IPS seamlessly integrates with the existing security stack, including firewalls, antivirus solutions, and Security Information and Event Management (SIEM) systems. Compatibility ensures a cohesive defense strategy.

In particular, evaluate the ability of the IDS or IPS to correlate alerts with other security events. This correlation, especially within the context of SIEM, provides a more comprehensive view of potential threats, aiding in quicker and more accurate incident response.

Cost and resource constraints

In addition to checking the purchase price (or licensing fee), be sure you understand the total cost (or annual cost) of ownership. In particular, make sure to consider the training and skill levels required for effective deployment and management. IDS may be more straightforward to operate, while IPS demands a deeper understanding of security protocols and its potential impact on network performance.

Related Resource:

What Is An Ips
What Is An Ids
What Does Ips Stand For
What You Need To Know About Ids Security
What You Need To Know About An Ids System