What Is A Network Firewall? - Benefits, Types, & Definition

What is a network firewall?

A network firewall is a security system that monitors and controls incoming and outgoing network traffic for segmentation and security purposes.

Firewalls filter incoming and outgoing network traffic based on an organization’s previously established security policies. At its core, a network firewall scrutinizes each data packet that attempts to enter or exit the network, deciding whether to allow or block it based on defined rules. This critical security component ensures that unauthorized access is prevented while allowing legitimate traffic to flow seamlessly, safeguarding the integrity, confidentiality, and availability of networked resources.

Foundation of the Nile Access Service, Nile Service Blocks integrate with external network firewalls and are designed to enable edge-to-cloud zero trust security. They enforce user and device authentication policies at the enterprise network edge. The Defense Hub within the Nile Services Cloud allows for dynamic orchestration of security policies per user and device, integrating with external security systems to enforce comprehensive security measures. Nile Service Blocks eliminate lateral movement thanks to industry’s first zero trust networking implementation that isolates every authenticated and authorized device at Layer 3. This integration between the Nile Service Blocks and external firewalls allows for a cohesive security posture, extending cloud-born zero trust security principles to campus and branch networks.

Why network firewalls are important

Network firewalls are pivotal in ensuring the security and integrity of an organization’s digital assets. They act as a barrier that shields internal networks from malicious entities and unauthorized access on the internet. By scrutinizing every packet of data that passes through, firewalls prevent potential threats such as viruses, worms, and hackers from infiltrating and compromising the network. 

Additionally, they play a crucial role in enforcing data policies and compliance standards, making them indispensable for organizations of all sizes in maintaining their operational security posture and protecting sensitive information.

Benefits of a network firewall

Network firewalls offer a level of security, compliance, and network management that goes well beyond the capabilities of standard home routers or basic firewalls. While home routers provide fundamental security features suitable for personal use, network firewalls bring advanced security protocols such as zero trust principles, sophisticated authentication mechanisms, and intrusion prevention systems. These advanced features ensure a significantly stronger security posture, essential for organizations facing complex cyber threats. 

Network firewalls enable precise policies and control over network traffic, ensuring compliance with regulatory standards and internal policies, a requirement that’s often required by businesses both large and small.

What does a network firewall do?

A network firewall serves as a gatekeeper for an organization’s network, meticulously inspecting, and managing the flow of incoming and outgoing traffic based on a comprehensive set of predefined security rules. These rules meticulously evaluate various aspects of the data packets, such as source and destination IP addresses, port numbers, and the types of protocols used, to determine their legitimacy and relevance to the organization’s security policies.

The firewall’s capabilities extend beyond simple traffic filtering; it plays a crucial role in thwarting cyber threats such as viruses, worms, and attempted breaches by malicious actors. By scrutinizing packet data, firewalls can identify and block potentially harmful traffic, preventing it from reaching the internal network. Furthermore, advanced firewalls are equipped with sophisticated features like stateful inspection, which tracks the state of active connections and makes decisions based on the context of the traffic, and deep packet inspection, which examines the data within the packet to uncover hidden threats.

Firewalls are instrumental in implementing network segmentation. This critical function divides the larger network into smaller, controlled segments or subnetworks, each with its own set of access controls. Network segmentation enhances security by limiting the access rights to sensitive information and systems, thereby reducing the attack surface within the organization. It also helps in containing and isolating potential security breaches, minimizing the impact and spread of cyber attacks within the network.

In essence, the network firewall embodies the frontline defense mechanism, empowering organizations to safeguard their network infrastructure from a wide array of cyber threats while ensuring the secure and controlled dissemination of information across their networks.

Technical terms for network firewall installation

When installing a network firewall, several technical terms are essential for understanding the process and ensuring effective deployment. Here is a breakdown of key terms:

Network Access Control (NAC)

NAC is an older security solution that enforces policy compliance on devices attempting to access network resources. It assesses and authorizes devices based on predefined security policies before granting access, enhancing the network’s overall security posture. 

VLANs (Virtual Local Area Networks)

VLANs are older technology that is used to segment network traffic logically, creating distinct broadcast domains within a single physical network infrastructure. This segmentation helps in managing and securing traffic flow, as well as in applying distinct policies for different user groups or device types.

Static ACLs (Access Control Lists)

Static ACLs are a legacy way to create sets of rules applied to router or switch interfaces to control the flow of traffic entering or exiting a network. These lists can permit or deny traffic based on IP addresses, ports, or protocols, providing a basic layer of security by filtering unwanted traffic.

TPM (Trusted Platform Module)

TPM is a secure crypto-processor that enhances hardware security by integrating cryptographic keys into devices. It provides hardware-based security functions, including secure generation of cryptographic keys, and can be used to ensure network devices’ integrity.

MACSec (Media Access Control Security)

MACSec provides encryption and secure communication on Ethernet links. It is a security technology that protects data-in-transit in network equipment, preventing eavesdropping and ensuring data confidentiality and integrity.

802.1X

This is a network protocol that provides an authentication mechanism for devices wishing to securely connect to a LAN or WLAN. It is part of the IEEE 802.1 group of networking protocols and ensures that only authorized devices can connect to the network.

SSO (Single Sign-On) for BYOD (Bring Your Own Device)

SSO for BYOD solutions streamline user authentication by allowing a single set of login credentials to access multiple applications, reducing the number of sign-ins for users and enhancing security for devices that employees bring to the network.

Device Profiling

Device profiling involves collecting and analyzing data about devices connected to the network to identify them accurately. This information can be used for various purposes, including enforcing security policies, granting access levels, and ensuring compliance with network policies.

What are the main components of network firewalls?

Packet filtering

Packet filtering represents the most basic form of firewall technology. It operates by inspecting each data packet’s header as it passes through the firewall, comparing the source and destination IP addresses, port numbers, and protocol type against a predefined set of rules. Based on these criteria, the firewall decides whether to allow or block the packet. This component is crucial for establishing a preliminary layer of security by regulating access to and from the network.

Stateful inspection

Stateful inspection, or dynamic packet filtering, adds a layer of intelligence to the firewall’s capabilities. Unlike simple packet filtering, this component tracks the state of active connections and makes decisions based on the context of the traffic. It ensures that only packets matching a known active connection are allowed through, enhancing the firewall’s ability to detect and block unauthorized access attempts.

Proxy services

Proxy services act as intermediaries between end-users and the Internet, providing both security and privacy benefits. By processing and forwarding requests on behalf of the user, the proxy can enforce content filtering, perform deep packet inspection, and obscure the user’s actual IP address. This component is particularly valuable for protecting against web-based threats and controlling internet usage within an organization.

Network address translation (NAT)

Network address translation plays a pivotal role in conserving IP addresses and enhancing privacy. NAT modifies the IP address information in packet headers as they pass through the firewall, allowing multiple devices on a private network to share a single public IP address. This obfuscation technique not only conserves IP addresses but also adds an additional layer of difficulty for external threats trying to pinpoint internal network resources.

Virtual private network (VPN) support

Incorporating VPN support into firewalls enables secure remote access to the network. This component encrypts data traffic between the remote user and the firewall, safeguarding sensitive information over public networks. VPNs are essential for businesses with remote or mobile employees, providing them with secure access to internal resources regardless of their location.

Intrusion detection and prevention systems (IDPS)

Intrusion detection and prevention systems complement the firewall’s protective measures by monitoring for suspicious activity and potential policy violations. IDPS can detect a wide range of malicious behaviors and attacks, automatically taking action to block the threats and alerting network administrators. This proactive approach is often used for East-West traffic and helps in early detection and response to cybersecurity threats.

User identity management

User identity management integrates with the firewall to apply security policies based on individual user identities rather than just IP addresses. This allows for more granular control over network access, enabling organizations to implement tailored security policies that reflect the roles and responsibilities of each user. Identity-based rules enhance security by ensuring that users have access only to the resources necessary for their work.

Application awareness

Next-gen application-aware firewalls provide deep visibility into the applications generating network traffic, regardless of the port or protocol used. This enables administrators to enforce policies that control application use within the network, blocking unwanted applications while allowing business-critical ones. Application awareness is key to preventing the misuse of network resources and protecting against application-layer attacks.

Security features of a network firewall

A network firewall is equipped with a myriad of security features designed to protect an organization’s network from various cyber threats. Here are some of the critical security features that are commonly found in network firewalls:

Zero trust principles

A network firewall implementing zero trust principles operates on the assumption that no entity inside or outside the network is trusted by default. Every access request, regardless of origin, is authenticated, authorized, and continuously validated for security compliance before granting access to network resources.

Authentication and authorization

Network firewalls ensure secure access by authenticating and authorizing all entities attempting to access the network. This includes mechanisms like 802.1x for user authentication, Single Sign-On (SSO) for BYOD (Bring Your Own Device) scenarios, and device profiling for IoT devices, ensuring that only verified users and devices can access network resources.

Hardened hardware and encryption

To protect the network, firewalls utilize hardened hardware with security features like Trusted Platform Modules (TPM) and MACsec encryption. These features help in securing the hardware against tampering and ensuring that data in transit is encrypted and protected from eavesdropping or interception.

Dynamic access control

Instead of relying on legacy static Access Control Lists, modern network firewalls use dynamic rules that adapt to the changing network environment. This dynamic approach to access control ensures that security policies are effectively enforced even as users and devices move within the network or their attributes change.

Continuous security compliance

Network firewalls play a crucial role in maintaining continuous compliance with cyber insurance requirements and reducing the network’s attack surface. This includes regular updates, security patches, and adherence to security standards and certifications like ISO 27001, SOC2 Type II, and CSA Level 1.

Network segmentation

Firewalls enable segmentation within the network, isolating authorized users and IoT devices to protect them from potential threats. This segmentation is crucial for minimizing the attack surface and containing threats should they penetrate the network perimeter.

Visibility and monitoring

Comprehensive visibility across the network stack, including wireless Intrusion Detection Systems (IDS), is another critical feature of network firewalls. This visibility helps in identifying and mitigating potential security threats, ensuring that the network remains secure.

Types of network firewall

Network firewalls can be categorized based on their filtering mechanisms and operational functionalities. Here are the main types:

Packet filtering firewalls

These are the simplest type of firewalls that make decisions based on the information in the packet header. They inspect source and destination IP addresses, port numbers, and the protocol to allow or block traffic. Despite their simplicity, packet filtering firewalls are effective for basic network security needs.

Stateful inspection firewalls

Also known as dynamic packet filtering firewalls, they not only inspect packet headers but also keep track of the state of active connections. By maintaining a state table, these firewalls can understand the context of traffic flow, allowing them to make more informed decisions about which packets to allow or block.

Proxy firewalls

Operating at the application layer, proxy firewalls act as intermediaries between end-users and the services they access. They can inspect the content of traffic, ensuring deep data analysis and filtering capabilities. Proxy firewalls can effectively prevent data breaches and detect application-specific vulnerabilities.

Next-generation firewalls

NGFWs combine the capabilities of traditional firewalls with advanced features like deep packet inspection (DPI), intrusion prevention systems (IPS), and application awareness. They provide comprehensive security features that can enforce policies based on applications, users, and groups, offering a more granular control over network traffic.

UTM firewalls

UTM firewalls integrate a variety of security features in a single appliance, including anti-virus, anti-spam, content filtering, and intrusion prevention. They are designed for ease of use, providing a consolidated interface for managing a broad array of security functions.

Cloud firewalls

Also known as firewall-as-a-service (FWaaS), cloud firewalls are gaining in popularity and are hosted in the cloud to provide network security for cloud-based resources. They offer scalability, high availability, and ease of deployment, making them suitable for protecting distributed networks and mobile users.

Network segmentation firewalls

These firewalls are used to create secure zones within networks, allowing organizations to isolate critical systems and sensitive data. By controlling traffic flow between segments, they help reduce the attack surface and limit the potential impact of breaches.

Nile Access Service simplifies the complex process of choosing the right firewall for organizations by offering a comprehensive network security solution that is designed to meet the diverse needs of modern enterprises. Nile works with industry’s most popular firewalls such as those from Palo Alto Networks for comprehensive security in any environment.

Leveraging AI, zero trust principles, and a user-centric design, the Nile Access Service ensures that organizations benefit from robust security features, including built-in isolation per segment, stateful inspection, intrusion prevention, and advanced threat protection. By integrating seamlessly with existing IT infrastructure, Nile Access Service enables organizations to extend their zero trust networking security posture to campus and branch environments, without the need for extensive configuration or management overhead. It offers industry’s first enterprise network that is purpose designed to isolate every authenticated and authorized device within the network at Layer 3, completely eliminating the risk of lateral movement and preventing proliferation of malware and ransomware. 

Use cases of network firewall

Network firewalls, integral to securing modern digital infrastructures, have a variety of use cases across different sectors. Here are key scenarios where network firewalls play a crucial role:

Protecting against external threats

Network firewalls are the first line of defense against external threats such as hackers, malware, and other cyberattacks. By scrutinizing incoming and outgoing traffic, they prevent unauthorized access and protect sensitive data from being compromised.

Enforcing compliance and security policies

Organizations can use network firewalls to enforce security policies and comply with regulatory standards. This includes controlling access to restricted content, blocking unauthorized applications, and ensuring data is encrypted and secure.

Segmenting the network

Firewalls enable organizations to segment their network into secure zones, each with distinct security policies. This segmentation is vital for protecting sensitive areas of the network, limiting the spread of potential attacks, and ensuring that only authorized users can access critical resources.

Secure remote access

With the rise of remote work, network firewalls provide secure VPN connections for remote employees, ensuring that their communications are encrypted and protected from interception. This use case is particularly relevant for organizations that rely on a mobile workforce.

Monitoring and logging network activity

Network firewalls offer detailed logging and monitoring capabilities, allowing organizations to track network activity, identify suspicious behavior, and respond to incidents in real-time. This information is crucial for forensic analysis and understanding the nature of security threats.

Optimizing network performance

Some advanced firewalls come with features that can help optimize network performance, such as bandwidth management and quality of service (QoS) settings. These features ensure that critical applications receive the necessary bandwidth, improving overall network efficiency.

Robust network protection and performance with Nile

Nile Access Service offers a seamless network experience that aligns with your strategic business requirements, eliminates network complexity when it comes to zero trust security enforcement and shares the responsibility for IT team’s success. With Nile, you can rest assured knowing that built-in zero trust campus security and robust integration partnerships are transforming network security and compliance measures. 

Nile also offers usage-based billing for scalable, flexible consumption.network availability, coverage, and capacity are guaranteed.

Discover how Nile can extend zero trust security to your campus and branch network.