What is IPS Security?

What is IPS Security?

An Intrusion Prevention System (IPS) is a security solution designed to identify and block attacks against an organization’s systems. An IPS can be deployed at the network level (NIPS), monitoring network traffic and protecting all systems on the protected network, or on a particular host (HIPS), protecting only that server.

IPS Security: Complementing the Firewall’s Capabilities

An IPS is an integral component of an organization’s network security strategy because it can identify and block threats that other solutions do not. For example, a firewall is primarily designed to restrict traffic using certain ports and protocols from entering or leaving a protected network. On its own, it lacks the ability to identify and block malicious content within accepted protocols.

One of the primary differentiators between a traditional firewall and a UTM (Unified Threat Management) is that a UTM incorporates an IPS. The IPS inspects the contents of network traffic and blocks traffic based on known threats, suspicious anomalies, or corporate policy. This deeper inspection complements a firewall’s capabilities and enables an organization to protect itself against modern, more sophisticated cyber threats.

The Difference Between IPS and IDS

Intrusion detection systems (IDSs) and IPSs are the same solution operating in different modes.

The primary difference between an IDS and IPS lies in how they respond to an identified threat. An IDS is intended to simply identify a threat and alert security personnel about it, triggering a response. An IPS goes a step further, actually blocking the attack and preventing it from reaching the target system as well as alerting security personnel.

What Does IPS Protect Against?

An IPS can use various techniques to identify potential threats to an organization’s systems. These include:

  • Signature-Based Detection: Signature-based detection identifies known threats based on unique features of the threat. For example, an IPS may look for the deviation from standard communication protocol definitions or signs of communication with known malicious domains.
  • Anomaly-Based Detection: Anomaly-based detection uses machine learning (ML) to identify unusual or suspicious activities that might indicate a potential threat to an organization’s systems. For example, an extremely high volume of traffic to a distant country the enterprise doesn’t have customers in may point to a potential attack..
  • Policy-Based Detection: Security administrators can define policies within the IPS that specify which types of traffic should be permitted or blocked by the IPS. This could allow an organization to block traffic to known malicious or inappropriate sites and to otherwise enforce corporate security policies.

A modern IPS should incorporate signature-based, anomaly-based, and policy-based threat detection mechanisms. As a result, it can protect against a range of potential threats, including malformed packets, geo-political attacks, port scanning, and vulnerability exploitation.

Why security teams should always prefer IPS over IDS

An IDS and IPS are similar solutions, but an IPS is the superior choice. Three reasons for this include attack prevention, regulatory compliance, and policy enforcement.

Prevention of Attacks

An IDS identifies threats and generates an alert for security personnel to investigate and remediate. As a result, threats will reach target systems before they are remediated, creating a window for attackers to expand their reach, steal data, and cause damage to enterprise systems.

An IPS, on the other hand, blocks malicious content before it reaches the protected network or endpoint. This eliminates the potential cost and impact of the attack on the organization because the malicious content never executes on the target system.


Organizations are subject to an ever-growing array of data protection regulations such as PCI DSS, HIPAA, and the GDPR. One of the core requirements of these regulations is that organizations implement security controls that protect their systems and the sensitive data entrusted to them against unauthorized access.

While an IDS provides an organization with visibility into attacks against it, it does nothing to protect against these attacks, increasing the potential for data compromise. An IPS blocks identified attacks before they reach their targets, protecting against unauthorized access to the sensitive data.

Active Policy Enforcement

Companies may have security policies for various reasons. Some may be designed to protect the business and maintain competitive advantage, while others may be driven by external regulatory requirements. Regardless of their source and intent, these policies only provide value to the organization if they are enforced.

An IDS provides no enforcement capabilities to the organization since all traffic that poses a threat to the organization or violates corporate policy is permitted to continue on to its destination. With an IPS, traffic that violates policy is blocked before it reaches its destination, providing effective policy enforcement.

IPS Security for the Distributed Enterprise

An IPS enables an organization to block malicious, suspicious, or inappropriate traffic intended for particular servers or networks. However, an IPS must be deployed in-line to block traffic, which dramatically limits its scope of protection.

As organizations become increasingly distributed, this becomes a significant issue. With servers and applications located on-prem, in the cloud, and offsite, an IPS deployed at the perimeter of the corporate network only protects the traffic flowing through that network. Rerouting traffic between remote sites — such as remote workers and corporate SaaS applications — creates significant latency and degrades network performance.

Eliminating this tradeoff between network performance and security requires deploying IPS as part of a secure access service edge (SASE) deployment. With SASE, traffic flowing over the corporate WAN is inspected at the nearest cloud-based PoP before being optimally routed to its intended destination. With Cato’s global network of PoPs, this enables an organization to provide IPS security everywhere to its distributed infrastructure without performance impact.