IPS vs. Firewall: What’s the Difference?

Due to the complexity of networks and the sophistication of cyberattacks, you need multiple network security layers to protect data, applications, and users. Two network security technologies commonly used for real-time traffic monitoring and threat protection are firewalls and intrusion prevention systems (IPSs).

To maximize protection for your network, it is essential to compare IPS and Firewall and learn when to use each technology.

The Role of Firewalls in Network Security

A firewall is a network security system that enforces a defined set of security rules by monitoring incoming and outgoing traffic. Positioned at the network edge, it acts as a barrier between a trusted internal network and untrusted external networks, such as the public internet.

By filtering traffic, firewalls aim to block malicious traffic while allowing legitimate communication without significantly impacting network performance.

Firewalls perform this filtering by examining data packets. They identify details, such as:

• The source/destination IP addresses
• Ports
• Protocols

Then compare this information against predefined policies to decide whether to allow or block traffic. More advanced firewalls may also perform deeper packet inspection.

By monitoring traffic at the network edge, firewalls are used to:

• Secure a network perimeter
• Enforce internal security policies
• Filter traffic to allow only approved communication

There are multiple firewall types with different capabilities, including:

• Packet-Filtering Firewalls: Inspect packets to allow or deny traffic based on IP addresses and ports.
• Stateful Inspection Firewalls : Tracks active connections to understand whether traffic is part of an established session.
• Proxy Firewalls (Application-Level Gateways): Intercepts all traffic between users and the internet and provides higher levels of security, such as inspecting application-layer data.
• Web Application Firewall : Protects applications by monitoring HTTP requests sent to them.
• Next-Generation Firewalls (NGFW): Modern solutions that combine traditional packet filtering with advanced features, including deep packet inspection, intrusion prevention systems, and application awareness. They can detect and block complex threats that legacy firewalls might miss.

The Use of Intrusion Prevention System (IPS)

An intrusion prevention system is a proactive network security solution that monitors network traffic in real time to detect and prevent malicious activities. When it comes to firewall vs IPS functionality:

• An intrusion prevention system analyzes the content of data packets to uncover threats
• A firewall primarily filters traffic based on IP addresses, ports, and protocols. If firewalls act as the first line of defense, IPS offers more in-depth scrutiny to mitigate any threats that may have slipped past

If an IPS identifies a threat, it can take immediate automated actions, including:

• Blocking malicious packets
• Quarantining infected devices
• Resetting connections
• Sending alerts to security teams

These real-time, proactive features are one of the key IPS benefits, minimizing the risk associated with malicious traffic. IPSs are positioned directly in the path of network traffic, usually behind the firewall, to inspect every packet as it flows into or out of your network.

An IPS can use various detection methods to identify threats, including:

• Signature-Based Detection: Compares traffic against a database of known attack signatures.
• Anomaly-Based Detection: Establishes a baseline of normal activity and flags deviations that could signal an attack.
• Policy-Based Detection: Enforces security policies defined by administrators.

5 BIGGEST Differences Between an IPS and a Firewall

Here are the 5 key differences when comparing IPS vs. firewall solutions.

#1. Primary Purpose

Firewalls control access to and from a network by enforcing security policies about what traffic is allowed or denied. In contrast, the primary purpose of an IPS is to detect and actively stop malicious activity within allowed traffic flows.

#2. Inspection

A core IPS and firewall difference is how deeply they inspect network traffic.

• Traditional firewalls primarily focus on packet headers to decide whether to allow or block traffic. They examine attributes such as source and destination IP addresses, ports, and protocols.
• An IPS routinely performs deep packet inspection. It doesn’t just look at where the data is going, it also analyzes what the data actually contains.

#3. Position

Another important distinction between a firewall and an IPS is where they are positioned in the network architecture.

• A network firewall is typically deployed at the very edge of a network. It is the first line of defense at the perimeter, enforcing broader access control and blocking unwanted traffic at the network’s entry points.
• An IPS should be positioned inline within the traffic path, generally directly behind the firewall. In this position, it can scrutinize traffic before it interacts with sensitive business systems, while still taking advantage of the firewall’s initial filtering.

#4. Response

Firewalls and IPSs respond to suspicious activity very differently.

• Typically, a firewall operates through static, rule-based decisions that either block or allow traffic.
• An IPS can provide more active and varied responses, including dropping the data packets, resetting connections, or quarantining affected systems.

#5. Performance Impact

IPS vs. firewalls have a different impact on network speed and efficiency.

With their simpler filtering mechanisms, vendors have optimized firewalls for fast network performance and minimal latency. Conversely, IPSs operate inline with the traffic flow and perform more in-depth analysis. This introduces latency, particularly in high-throughput environments.

When to Use IPS, Firewall, or Both

Not sure what solution to use or whether to combine them?

Here’s exactly what you need to decide. A firewall should be used when you want to:

• Protect the network perimeter and block unauthorized traffic
• Enforce security policies and control access to your network
• Monitor or log network traffic
• Deliver broader and faster security controls

In contrast, you should use an IPS to:

• Provide more specific threat detection and prevention
• Identify both known and unknown threats
• Proactively respond to malicious traffic

But, you shouldn’t think of network security in terms of IPS vs. firewall.

Integrating IPS and Firewall

Instead, you should look to integrate both IPS and firewall capabilities and identify solutions that provide the benefits of both to deliver multiple network security layers. Here’s an example of how that works:

• You position a firewall at the network edge to filter traffic based on source/destination information as well as the port and protocol in use.
• Then you can perform deeper packet inspection and real-time threat prevention utilizing an IPS.

Together, both IPS and firewall solutions deliver a multi-layered network security posture for more comprehensive coverage and protection from the wide range of threats.

Next Generation Firewalls and Beyond with Check Point

Next-generation firewalls provide comprehensive capabilities to integrate both IPS and firewall solutions into your network security strategy.

Check Point’s next-generation firewall offers the highest-rated threat prevention with a 99.8% block rate against zero-day attacks.