What is an Edge Firewall?

Published on: March 15, 2024

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11 min read

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For German Version

The internal and external networks are connected via the Edge Firewall or EdgeFW. In addition to supporting intrusion prevention system (IPS) and network antivirus (AV) features for EIPs, EdgeFW offers border security protection for traffic traveling north-south between the data center and external networks. In this article, we will cover the following topics related to edge firewalls:

• What is the purpose and role of an edge firewall in network security?
• How Does an Edge Firewall Differ from Other Types of Firewalls?
• What Are the Key Features and Functionalities of an Edge Firewall?
• What Are the Advantages of Deploying an Edge Firewall at the Network Perimeter?
• How Does an Edge Firewall Enhance Network Security for Organizations?
• What types of threats and attacks does an Edge Firewall protect against?
• Are There Different Deployment Models for Edge Firewalls, and What Are Their Advantages?
• How Does an Edge Firewall Fit into a Comprehensive Network Security Strategy?
• Can an Edge Firewall Help in Mitigating Distributed Denial-of-Service (DDoS) Attacks at the Network Edge?
• What role does threat intelligence play in the effectiveness of edge firewall protections?
• How do edge firewalls impact the performance and throughput of network traffic?
• How Can Organizations Ensure the Scalability of Edge Firewall Solutions as Their Network Grows?

What is the Purpose and Role of an Edge Firewall in Network Security?

A security program that guards the border between a private network and a public network is known as an edge firewall or perimeter firewall. Its objective is to stop undesired or dubious data from getting onto the network. Through the scanning of every data packet that attempts to join the network, it defends against cyberattacks and other harmful activity.

In order to provide an administrator with more control over user access, a perimeter firewall functions as a proxy service, acting as a middleman between users and the internet. Based on the data in the packet's header and payload, a perimeter firewall can determine whether a data packet represents a danger as it looks through its contents.

Both internal and external traffic can be filtered by a perimeter firewall. Traffic that moves between users, internal networks, and devices is referred to as internal traffic as it comes from within your network. Internet traffic that originates from outside the network is referred to as external traffic. Because there are millions of dangers on the internet that might target your firm, external traffic carries increased risk.

How Does an Edge Firewall Differ from Other Types of Firewalls?

Edge firewalls are distinct from other kinds of firewalls, including data center firewalls (also called internal firewalls) and client firewalls (sometimes called host-based firewalls), in a number of ways.

What is the Difference Between Edge Firewall and Client Firewall?

Network edge firewalls are mostly used to protect whole computer networks from intrusions and to control network traffic so that only authorized packets may get to your servers and IT assets. Using a network-based firewall as an Internet border device to keep a company's local area network (LAN) safe from the Internet is its most popular use.

A client firewall, also known as a host-based firewall, is a piece of software that is installed on host computers or servers in order to defend them from attacks. The client firewall is software that is placed directly on the host and controls traffic that enters and leaves the designated host.

A traditional illustration of a client firewall is the Windows Firewall, which comes preinstalled on all Windows OSs. This type of security is host-specific, meaning that it shields the host from any network to which it may be connected.

For example, your network firewall already protects you if you are connected to the network at work. Your laptop using a host-based firewall will remain protected even if it is connected to an external WiFi network.

What is the Difference Between Edge Firewalls and Datacenter Firewalls?

Datacenter firewalls are firewalls that are stateful, multitenant, network layer, and 5-tuple (protocol, source and destination port numbers, source and destination IP addresses). Traffic flows between east-west and north-south over standard VLAN networks and virtual networks are protected by the Datacenter Firewall. On the other hand, an edge firewall is responsible for monitoring the perimeter of a network and effectively preventing illegal access from external sources.

Unlike network edge firewalls, data center firewalls are intended to safeguard virtual machines. Additionally, they are designed to provide data centers with the agility they need, enabling administrators to redistribute virtual resources as needed without going against firewall policies.

What Are the Key Features and Functionalities of an Edge Firewall?

Below, you can find the key features and functionalities of an edge firewall:

1. Packet Filtering: A firewall's primary job is packet filtering, which looks through each packet's headers as it travels through it. Based on previously set rules or policies, the firewall can then decide whether to accept, reject, or drop the packet. The source and destination IP addresses, ports, protocols, and other details can be specified in these rules. Although packet filtering can stop undesired or dangerous traffic from entering or leaving your network, it is unable to examine the packets' contents or context.
2. Stateful Inspection: A more sophisticated feature of a firewall is stateful inspection, which keeps track of the context and state of every connection that goes through it. After that, the firewall can apply more specific rules or policies by comparing the packets to a database of known or reliable connections. Although stateful inspection necessitates greater memory and processing capacity, it can identify and stop attacks like spoofing, fragmentation, and others that attempt to get beyond packet filtering.
3. Network Address Translation (NAT): One of a firewall's functions is network address translation (NAT), which modifies the IP addresses of all traffic passing through it. Your network's private IP addresses can then be mapped by the firewall to public IP addresses, or vice versa. NAT increases your network's efficiency, scalability, or security, but it can also make traffic routing and reporting more difficult.
4. Proxy Services: A firewall's proxy service function serves as a bridge between two networks or devices. The traffic that flows via the firewall can subsequently be altered, filtered, or cached, and the endpoints' actual IP addresses can be concealed. Although proxy services might improve your network's performance, security, or privacy, they can cause compatibility problems or latency.
5. Deep Packet Inspection (DPI): Network packet filtering includes deep packet inspection (DPI), information extraction (IX), or comprehensive packet inspection (CPI). In order to prevent a packet from passing past an inspection point, deep packet inspection filters out any stated criteria, spam, viruses, intrusions, and non-compliance with the protocol from both the data portion and the header of the packet.
6. Application Layer Filtering: A firewall's ability to inspect the content and behavior of the traffic passing through it is known as application layer filtering. Then, the firewall may recognize and deny access to particular programs, protocols, or instructions that are not authorized or reliable. Application layer filtering can stop viruses, malware, and other dangers from taking advantage of an application's weaknesses or features, but it can also interfere with an application's ability to function or perform.
7. Intrusion Detection and Prevention (IDS/IPS): The purpose of an intrusion detection system (IDS) is to notify only about possible incidents so that an analyst at the security operations center (SOC) may look into the situation and decide whether or not more action is needed. In contrast, an intrusion prevention system (IPS) takes proactive measures to prevent attempted intrusions and/or resolve related issues.
8. Logging and Reporting: The process of generating a log file of every action that goes through the firewall is known as firewall logging. Everything from unsuccessful attempts to connect to the network to successful connections and everything in between can be included in this log file of activities.
9. VPN Support: A firewall's ability to provide a safe, encrypted tunnel between two networks or devices is known as a VPN service. The traffic can then go over the firewall without being seen or intercepted by outside parties. VPN services can improve your network's accessibility, security, or privacy, but they may also call for extra setup or authentication.
10. Load Balancing: Multiple firewall systems are positioned behind server load balancers in a deployment architecture known as firewall load balancing. The firewall systems load balance network traffic among themselves, resulting in a highly available and scalable security infrastructure.
11. High Availability: A firewall system that guarantees network protection even in the event of a firewall device failure is known as a high availability (HA) firewall. Redundancy eliminates single points of failure and offers constant security coverage.
12. Security Policies: Based on the information security rules of the business, a firewall policy specifies how the firewalls of that organization should manage incoming and outgoing network traffic for certain IP addresses and address ranges, protocols, applications, and content kinds.
13. Threat Intelligence Integration: Cyber Threat Intelligence is the result of applying sophisticated analytic algorithms to collect and analyze cybersecurity data from several sources. Cyber threat intelligence (CTI) providers are able to extract actionable information and insights that assist their clients in identifying and preparing for cyber threats by gathering copious quantities of data on current cybersecurity risks and trends and running analytics on this data.
14. Content Filtering: The technique of controlling or screening access to particular emails or websites is known as content filtering. Blocking content that contains damaging information is the aim.
15. User Authentication: When a user logs into the network, a firewall agent searches Active Directory for information and sends it to the firewall. As a consequence, the firewall detects that a user is already logged into the network when they attempt to bypass a policy that demands authentication.
16. QoS (Quality of Service): A collection of technologies known as quality of service (QoS) operates on a network to ensure that it can consistently handle high-priority traffic and applications even with constrained network capacity. By offering distinct handling and capacity allocation to particular network traffic flows, QoS systems achieve this.

What Are the Advantages of Deploying an Edge Firewall at the Network Perimeter?

The line separating a public network from a private network is established and maintained by a perimeter or edge firewall. There are advantages and disadvantages to using perimeter firewalls for an organization's overall security posture. The following are some advantages that an edge firewall offers:

• Network Traffic Visibility: Every packet coming into and going out of the private network is visible to a perimeter firewall. This facilitates company security and offers useful data on the utilization of both internal and external services.
• Malicious Content Filtering: When used as a perimeter firewall, an NGFW can recognize and prevent malware and other threats from accessing a company's network.
• Enhanced User Privacy: By serving as a middleman between internal users and external servers, perimeter firewalls can improve user privacy.
• Data Loss Prevention: By detecting and restricting traffic that deviates from corporate rules, perimeter firewalls can aid in preventing the loss of important and sensitive data.

How Does an Edge Firewall Enhance Network Security for Organizations?

Edge firewalls, the main line of protection against assaults, use a variety of strategies to regulate traffic flowing between an organization's network and untrusted networks. Let's talk about a couple of them.

• Static packet filtering: Through the use of packet fields and network administrator rules, the firewall filters traffic using the static packet filtering approach. Every packet that a static packet filter receives is examined and cross-referenced with ACLs. The traffic is then either allowed or denied entry into the organization's network according to the rules. Operating at layers three and four of the open systems interconnection (OSI) paradigm, static packet filtering is one of the more traditional firewall strategies. It is therefore unable to distinguish between the various application layer protocols. It is also unable to stop spoofing attempts.
• Proxy-based firewalls: An intermediary between end users and the public network is a proxy-based firewall. The proxy server establishes a second connection to the public network on behalf of the hosts. In order to enforce network regulations, a proxy server can filter packets prior to their transmission to the public network. In order to shield the end user's IP address from the untrusted network, it can also disguise it.
• Stateful packet inspection: Stateful packet inspection, also known as dynamic packet filtering, actively tracks a network's connection status. These firewalls can, for example, forego monitoring incoming traffic if the packet has already been examined by keeping track of the state of current connections. Stateful packet inspectors improve network speed and stop spoofing in this way.
• Next-generation firewall (NGFW): To provide enterprise-wide security, a typical NGFW combines stateful inspection with static packet filtering, and it includes capabilities like deep packet inspection (DPI). To further improve security, it includes cutting-edge security features like malware and antivirus filtering, network security systems (IDS and IPS), and antivirus software.

What Types of Threats and Attacks Does an Edge Firewall Protect Against?

The major types of threats and cyberattacks that edge firewalls protect against are outlined below:

1. Unauthorized Access: Unauthorized access occurs when someone uses a device, application, network, endpoint, or data belonging to an organization without authorization. It is closely associated with authentication, which is the procedure that confirms a user's identity upon system access.
2. Malware and Viruses: Any software or program designed with the intention of causing damage to a computer, network, or server is known as malware or malicious software. The reason malware is the most prevalent kind of cyberattack is that it includes a wide range of attack types, including ransomware, trojans, spyware, viruses, worms, keyloggers, bots, cryptojacking, and any other assault that employs software for bad purposes.
3. Denial-of-Service (DoS) Attacks: A hostile, targeted assault known as a denial-of-service (DoS) attack overloads a network with erroneous requests in an attempt to interfere with company activities.
4. Distributed Denial-of-Service (DDoS) Attacks: A denial-of-service (DDoS) assault occurs when an adversary floods your network with traffic, blocking users from using important applications.
5. Intrusion Attempts: An intentional, unapproved effort to gain access to a computer, system, or network in order to alter or remove data or make a system unreliable is known as an intrusion attempt.
6. Phishing and Social Engineering: One of the most frequent risks to network security is phishing, in which a cyber-criminal uses social engineering to get your personal information under the premise of a phony email from a known source. You can unintentionally give up your login credentials and other important information by clicking on it.
7. Spam: Spam is any unsolicited communication sent in bulk. Usually sent via email, spam is also distributed through text messages (SMS), social media, or phone calls. Spam messages often come in the form of harmless (though annoying) promotional emails. But sometimes spam is a fraudulent or malicious scam.
8. Port Scanning: Hackers frequently utilize a port scan to find weak spots or open doors in a network. Cybercriminals can locate open ports and determine whether they are receiving or transmitting data by using a port scan attack. It can also show whether a business uses firewalls or other active security equipment.
9. Application Layer Attacks: Application-layer attacks concentrate on certain weaknesses in programs that let attackers stop the program from operating as intended. Application-layer attacks usually aim to overload servers or networks by overcrowding them or hogging resources to the point that requests and services from authorized users are either not fulfilled or served too slowly.
10. Zero-Day Exploits: A zero-day, often referred to as a 0-day, is a security flaw in a computer system that its creators, owners, or anybody else who may mitigate it is unaware of. Threat actors may use a zero-day exploit, also known as a zero-day attack, to take advantage of the vulnerability until it is fixed.
11. Insider Threats: IT teams only see half the picture when they concentrate primarily on identifying enemies outside the company. Internal actors, such as present or former employees, are known as insider threats. They represent a risk to an organization because they have direct access to confidential information, intellectual property (IP), and the company network. They also have knowledge of company policies, procedures, and other details that could be useful in launching an attack.
12. Data Exfiltration: Data theft is the deliberate, unapproved, covert movement of data from a computer or other device. It is sometimes referred to as data extrusion, data exportation, or data exfiltration.
13. Botnet Command and Control Traffic: An assault known as "command and control" uses tools to interact with and take control of a compromised system or network. A hacker requires a covert route or backdoor between their server and the compromised network or computer in order to profit from a virus assault for as long as feasible. The command-and-control server, often known as the C2 server, is the name given to the cybercriminals' server, which may be a single device or a botnet of devices.
14. Content-Based Threats: Content spoofing is an attack against a user that is made feasible by an injection vulnerability in a web application. It is also known as content injection, "arbitrary text injection," or virtual defacement. An attacker can provide material to a web application, usually via a parameter value, that is mirrored back to the user when the program improperly handles user-supplied data. As a result, the user gets shown a changed page inside the framework of the trusted domain. The fact that this attack makes use of a trust issue with users and a code-based vulnerability makes it frequently utilized as part of or in addition to social engineering.
15. Malicious Attachments: Malicious email attachments are designed to infect a user's computer. Attachments that seem to be voicemails, documents, PDFs, or e-files may be included in these fraudulent emails. Attackers want to install malware that may steal and harm data by attaching these files to emails. Certain viruses can grant an attacker total control over a victim's computer, allowing them to see the screen, log keystrokes, and connect to additional network systems.
16. Data Loss: When important or private information on a computer is compromised via theft, user mistake, viruses, malware, or power outages, data loss happens. It might happen as a result of an edifice's equipment malfunctioning or suffering physical damage.
17. Ransomware: Like viruses and worms, ransomware is able to spread throughout a network. Until a specified ransom demand is satisfied, this malicious program has the power to lock you out of your computer programs or, in the other case, your entire computer system.
18. Brute Force Attacks: A brute force attack is a methodical way to guess encryption keys, login passwords, and other information by using trial and error. The assailant keeps trying different usernames and password combinations until they eventually guess correctly.
19. DNS Attacks: DNS tunneling is a kind of cyberattack that uses DNS queries and answers to send code and data over a network while evading conventional security measures. After gaining access, the hacker is free to carry out command-and-control operations. By slowly encoding the data in a succession of DNS answers, this tunnel provides the hacker with a means of releasing malware and/or extracting data, IP addresses, or other sensitive information.
20. Man-in-the-Middle (MitM) Attacks: An attack known as a "man-in-the-middle" occurs when a hacker listens in on a conversation between two targets with the intention of obtaining banking information, passwords, or personal information. Additionally, the attacker may try to persuade the victim to change their login information, finish a transaction, or start a money transfer.

Are There Different Deployment Models for Edge Firewalls?

Yes, the following techniques can be utilized to install firewalls:

1. Hardware: Appliances placed at a network's edge are usually used in hardware firewall installations.
2. Software: Computers or servers at the network's edge can be equipped with software firewalls, which can approve or deny requests.
3. Cloud-based: A cloud firewall checks traffic that tries to access a storage application while safeguarding cloud storage systems and applications. It is housed in a cloud environment.

Can an Edge Firewall Help in Mitigating Distributed Denial-of-Service (DDoS) Attacks at the Network Edge?

No. A firewall may mitigate the impact of a DDoS attack, but it cannot provide comprehensive security. Firewalls traditionally use stateful packet inspection (SPI) to monitor the status of network traffic and assess the potential risks associated with incoming traffic and resource demands. However, the inherent statefulness of firewalls renders them vulnerable to state-exhaustion attacks, such as TCP flood attacks. In addition, they lack the ability to monitor DDoS attack traffic or effectively collaborate with cloud-based solutions to counteract these assaults.

A firewall may be designed to selectively restrict network traffic by denying packets that satisfy certain criteria. Implementing these measures may effectively obstruct a portion of the unauthorized network traffic used in Distributed Denial of Service (DDoS) attacks.

A firewall restricts the number of concurrent connections originating from a solitary IP address or a subnet. This feature aids in mitigating server resource overload caused by a high volume of requests originating from a single source.

Nevertheless, firewalls are not fully effective when it comes to mitigating DDoS attacks. When faced with a potent DDoS attack that generates a substantial amount of traffic, a firewall can be incapable of managing all incoming requests. Consequently, the firewall might constitute a weakness in the network architecture. In addition, assailants have the ability to alter or counterfeit the originating IP address, hence complicating the process of filtering at the firewall level. Hence, a firewall may serve as an extra defensive barrier against DDoS attacks, exploitation of vulnerabilities, or interception of communications. To enhance the reliability and efficiency of security, it is advisable to use specialized solutions that include systems for detecting and mitigating DDoS attacks.

What are the Best Practices for Deploying a Firewall with DDoS protection?

You may implement a firewall in conjunction with DDoS protection by following the next best practices:

1. Establish fundamental security measures by implementing a firewall.
2. Configure settings to selectively screen network traffic and prohibit dubious connections at the network layer.
3. Establish regulations that restrict the number of concurrent connections originating from a solitary IP address.
4. Utilize the firewall to block recognized undesirable IP addresses or networks.
5. Select a DDoS protection service and set up your network to route traffic via the company's system.
6. Consolidate the firewall and DDoS protection to ensure their collaborative functionality. In order to do this, it is necessary to synchronize the rules and settings between the firewall and the DDoS protection service.
7. Assess the effectiveness of your defensive measures and adapt your firewall and DDoS protection settings accordingly in response to emerging threats and assaults.
8. Contemplate using automation for your system's reaction to DDoS assaults. When a threat is identified, the firewall and DDoS protection systems may promptly respond by obstructing harmful network traffic.
9. Consistently analyze the traffic and activity of your network using a Web Application Firewall (WAF) or other analytical tools.
10. Regularly revise and modify firewall configuration rules in response to existing threats.

What Role Does Threat Intelligence Play in the Effectiveness of Edge Firewall Protections?

Technical threat intelligence, which is mostly data-centric, offers details on harmful indications, such as hashes of malware linked to threat actors and their IP addresses, domain names, and URLs. Firewalls, intrusion detection systems, and antivirus software are the main systems that employ cyber threat intelligence (CTI) to recognize and stop known threats.

How Do Edge Firewalls Impact the Performance and Throughput of Network Traffic?

Although firewall rules are essential for network security, they may also have an impact on performance. Every data packet that goes via a firewall must undergo scrutiny to ensure compliance with the established regulations, which require a certain level of computational analysis. The inspection procedure has the potential to cause higher CPU use and may affect the overall performance of the network.

Firewall rules offer an extra level of processing that might result in higher CPU use. When firewalls are dealing with a substantial amount of traffic or intricate rule sets, this additional burden may have a major impact on the overall performance of the network.

Firewalls might unintentionally slow down data transmission as they examine each packet against their set of rules. This may be especially evident in busy circumstances, when the firewall's processing capacity may restrict the network's total data throughput rate. Services such as IPS, SSL, or VPN increase the computational burden on the firewall, which might decrease the total throughput. For instance, when a firewall is actively engaged in scanning for malware or doing SSL inspection, its capacity to handle traffic may be lower than its maximum rated throughput.

Packet inspection time refers to the duration it takes for firewall rules to examine each packet and determine whether it should be permitted or denied. The process of inspecting and making decisions that rules require may cause delays, affecting the time it takes for data to move from its source to its destination. The inspection procedure, while efficient, might pile up and lead to a little delay, especially for time-sensitive activities such as video conferencing or online gaming.

Elaborate rules that include thorough packet inspection or filtering at the application level might lead to heightened latency. These regulations need additional processing time for analysis and decision-making, which may result in perceptible delays in data transfer.

How Can Organizations Ensure the Scalability of Edge Firewall Solutions as Their Network Grows?

To enhance the scalability and adaptability of your firewall setup, it is advisable to use automation and orchestration technologies capable of executing operations such as provisioning, deployment, and maintenance of your firewalls. Automation may assist in minimizing the need for human labor, enhancing productivity, and guaranteeing adherence to regulations. Orchestration facilitates the coordination and integration of firewalls with other components of a telecommunications system, including routers, switches, and servers, in order to provide a smooth and protected network.

Managing numerous firewalls poses the problem of maintaining consistency and ensuring updates are applied uniformly across various locations and devices. A centralized management solution may streamline this work by enabling you to setup, monitor, and troubleshoot your firewalls from a unified interface. Additionally, a centralized administration tool may be used to simultaneously enforce policies, rules, and configurations across different firewalls, resulting in time savings and minimizing the occurrence of human mistakes.

Implementing a modular and hierarchical architecture allows for the organization of firewall settings into smaller, manageable parts that can be easily reused and adjusted as required. One way to illustrate this is by creating modules that serve distinct purposes, such as filtering, logging, or authentication. These modules may then be implemented across several zones, interfaces, or protocols. Additionally, it is possible to establish hierarchies to manage various degrees of access, such as internal, external, or DMZ, and allocate them to distinct groups, users, or roles.

Utilizing templates and variables may enhance the efficiency and flexibility of your firewall setup, aiding in its creation and maintenance. Templates facilitate the establishment of the fundamental framework and specifications of your firewall setup, including elements such as ports, protocols, and addresses. Variables may be used to tailor the values of parameters based on various contexts, such as geographical locations, devices, or settings. By using templates and variables, you may generate several iterations of your firewall setup without the need for code duplication or rewriting.

Firewall-as-a-Service (FWaaS) offers enterprises a scalable and secure cloud-based solution that enhances security and provides flexibility.

FWaaS is a kind of managed security solution that offers firewall capabilities as a service hosted in the cloud. The process involves rerouting an organization's internet traffic via the cloud infrastructure of the service provider. During this process, the traffic is thoroughly examined for any risks and then permitted or denied access according to predetermined regulations.

Scalability is a key advantage of FWaaS. Organizations are required to make expensive investments in hardware and software solutions to meet their expanding requirements while using conventional firewalls. FWaaS allows enterprises to conveniently add or remove firewall resources as necessary, giving them the adaptability to expand or contract their security architecture according to their individual needs.