Cyber attacks can have severe financial consequences for businesses. Firewalls for network security are the foundational pillars in any cyber security architecture.
In this Article
- What are Firewalls
- How Firewalls work in today’s IT Networks
- Firewall optimization for safe, smooth IT networks
- Types of Firewalls
- Popular Firewall solutions- Comparison
- Things to consider before buying a Firewall solution
- Myths about Firewalls
- Final Thoughts
What are Firewalls
IT network firewalls are security systems that control network traffic, block data threats and enforce security policies to secure IT networks.
Traditionally, they filter data from an external network(e.g. internet), and then allow, or block its entry to an internal network. This screening process is done based on set security rules, IP addresses and port numbers. Over time, they have evolved to support today’s advanced IT environments. A firewall solution can be hardware, software, or their combination. Let’s learn more.
Firewalls in modern IT setups
Modern day firewalls do more than simple gatekeeping. Today, they support hybrid work environments, multi-cloud deployments and IoT(Internet of Things) sprawl. Firewalls now do deep packet inspection and AI-powered threat detection. Also integrate well with advanced security frameworks like Zero Trust and SASE (Security Access Service Edge).
Traditionally, a firewall’s operations have been the following:
- Traffic Inspection:
Firewall monitors incoming and outgoing network traffic. It checks every data packet against security rules. - Blocking Threats:
In case of suspicious behavior, or attempt of unauthorized access, firewall denies access and stops malware from entering the network. - Enforces Security Policies:
Firewall controls users, apps, or services communicating with an IT network. That includes access control, traffic filtering, segmentation and isolation, application-aware policies, time and location constraints, logging and monitoring, automated response and compliance enforcement.
Example: Setting a rule to block e-commerce sites from your IT network. Then people can’t use the network for online shopping.
In modern IT setups, firewalls cater to endpoint and perimeter defenses in zero trust architectures, Secure Access Service Edge(SASE) frameworks and hybrid cloud environments. For layered protection, they often integrate with Security Information and Event Management (SIEM), Endpoint Detection Response (EDR) and Data Loss Prevention (DLP) tools.
Here are some areas where firewalls function in today’s IT networks:
1. Firewall-as-a-Service (FWaaS)
Cloud-delivered firewalls are growing in SASE architectures. Compared to traditional firewalls, these are more suitable in terms of scalability and centralized policy setting. Particularly useful in remote and hybrid workforce scenarios. Examples- Zscaler, Check Point, Cato Networks.
2. AI-Powered threat detection
AI powered firewalls are gaining traction these days. They use machine learning in behavioral analysis, reducing false positives in threat detection and zero-day threat detection(cyberattacks exploiting a previously unknown vulnerability before developers fix it).
3. Firewalls in hybrid environments
- In multi-cloud setups, firewalls are placed at the edge of each cloud environment to inspect ingress/egress traffic.
- In SD-WAN (Software Defined-Wide Area Network) deployments, firewalls come at the hub site in a hub-and-spoke SD-WAN architecture. This enables centralized security inspection.
- In micro-segmented networks, firewalls are distributed at workload level.
Firewall optimization for safe, smooth IT networks
Fundamentally, firewalls work towards providing IT network security so business operations run safe and smooth. Before exploring firewall operations, we need to understand some key metrics affecting their performance. They are data throughput, latency and security policy violations.
1. Throughput–
Throughput measures the rate at which data pass through the firewall in an IT network. It’s measured in Mbps(Megabits per second), or Gbps(Gigabits per second). If a firewall’s throughput is less than your network’s bandwidth, that can cause latency issues. So, for smooth running networks, It’s always better to keep your firewall throughput above your network bandwidth.
2. Latency-
Latency is the time taken by data to travel from its source to destination in an IT network. It’s also referred to as network delay. Generally, when a firewall comes in, the latency goes up. This happens because the firewall takes time to process, and then block unauthorized data. The extent of latency depends on the security rules set in the firewall. For optimal performance of your network, try to balance security rules with related latency issues.
3. Security policy violations-
Implementing data security policies in a network is a basic function of a firewall. Metrics in terms of policy violations such as number of blocked threats provide insights. Monitoring policy violations, and reviewing security policies in that light can improve the firewall’s performance.
How to better utilize firewall in your business
Now, let’s look at some best practices and how firewalls help secure your IT network.
- Firewall rule optimization:
For seamless and secure IT networks, setting clear rules in the firewall is basic. Sometimes, organizations struggle in this area, resulting in bloated or misconfigured rules. In firewalls, there are tools for auditing, cleaning up, avoiding mistakes like too permissive rules etc. In short, these tools support rule hygiene best practices. - Firewall integration with SIEM for real-time monitoring:
In addition to firewall rule optimization, feed your firewall logs into a Security Information and Event Management (SIEM) solution. SIEM gives you real-time analysis of security alerts from various systems in your IT network. These actionable insights help you address issues swiftly.
SIEM also helps automate evidence collection and generate audit-ready reports for compliance reporting. When an anomaly occurs, eg- A 10GB data download at 3AM, it helps reconstruct attack timelines, trace lateral movements, identify patient-zero and exfiltration paths. - From SIEM to SOC:
The messages from SIEM can be further routed to your company’s Security Operation Centre (SOC) dashboard(which manages overall security posture of an organization), email or ticketing systems. In addition, you can also set automated safety responses like isolating a host, or blocking an IP.
Together with the support of these security systems, you can monitor the whole network’s behavior. And continuous monitoring aids swift problem solving. The net result is a smooth IT network for your business operations.
Types of Firewalls
1. Packet Filtering Firewall
A packet filtering firewall does basic filtering of network traffic based on IP addresses, ports and protocols. These firewalls work faster but have limitations. This firewall does data filtering at the network layer, and inspects only data packet headers. In order to maintain session state, payloads are not analyzed here. So, the network may become vulnerable to spoofing due to its inability to spot application-layer threats.
2. Stateful Inspection Firewall
This type of firewall does smart filtering of network traffic by tracking its active connections. It maintains a state table having session details like IP addresses, ports and connection status. The state table helps stateful inspection firewalls to recognize, and then permit only legit return traffic. This dynamic awareness enables blocking of unsolicited packets. Also detects anomalies like spoofed or out-of-sequence traffic in the network.
3. Proxy Firewall
Proxy firewall acts as an intermediary between the internet and its users. It intercepts requests from clients in the firewall network and evaluates them against set security policies. Afterwards, it forwards approved traffic to the user end destination.
A proxy firewall masks internal IP addresses. It inspects traffic at the application layer. That protects data against threats like malware, phishing and exfiltration.
4. Next-Gen Firewall
Next-gen firewall comes with real-time threat intelligence and app awareness. It does deep packet inspection as well as behavioral analysis. In other words, it can identify and control apps regardless of port, protocol, evasive tactics, and enforce granular policies. These firewalls can block zero-day exploits, advanced persistent threats (APTs) and encrypted malware proactively.
5. Web Application Firewall (WAF)
WAF protects web apps from attacks like SQL (structured query language) injection and XSS (cross site scripting). It inspects http/s traffic, detects and blocks malicious payloads before they can reach the apps’ server. WAF enforces input validation, output encoding, and custom rules. That in turn, prevents exploitation of vulnerabilities in user input fields.
Popular firewall solutions: Comparison
Here’s a comparison of 3 popular firewall solutions- Fortinet FortiGate, Palo Alto Networks NGFW and Cisco Secure Firewall.
Firewall Feature | Fortinet FortiGate | Palo Alto Networks NGFW | Cisco Secure Firewall |
| 1. Security | Integrated IPS (Intrusion Prevention System), SSL (Secure Sockets Layer) inspection, web filtering, sandboxing | Industry-leading threat prevention, WildFire sandbox, App-ID, URL filtering | Strong IPS, malware protection, VPN(Virtual Private Network) support |
| 2. Performance | High throughput; efficient resource usage | Ideal for large-scale, high-performance environments | Solid performance; but may lag in complex deployments |
| 3. Ease of Use | Simple user interface(UI), fast deployment, great for SMBs (Small and Medium Businesses) | Advanced UI(User Interface), steep learning curve, ideal for security pros | Ideal for Cisco users; but licensing can be complex |
| 4. Scalability | Scales well for SMBs and large enterprises | Highly scalable, especially in cloud and hybrid setups | Scalable, but need more planning for large firms |
| 5. Cloud Integration | Strong support for hybrid cloud and SDWAN (Software Defined Wide Area Network) | Deep cloud-native integrations, Prisma Access, Cortex XDR (Extended Detection and Response) | Integrates with Cisco Umbrella and SecureX |
| 6. Pricing | Competitive, especially for SMBs | Premium, strong, enterprise-grade security | Mid-range to high, depending on deployment model |
| 7. Best for | SMBs, cost-conscious businesses | Firms that want advanced threat detection and Zero Trust integration | Companies having Cisco infrastructure already in place |
Key Takeaways:
- Fortinet FortiGate is affordable and easy to manage. Has strong security features. Excels in unified management across hybrid environments.
- Palo Alto Networks NGFW leads in innovation and threat intelligence. Offers advanced threat prevention and zero trust architectures. It has a premium price.
- Cisco Secure Firewall is ideal for Cisco-centric environments. It offers good integration and support.
Before buying a firewall solution for your business
When choosing one solution from several firewalls for your business network security,
- First assess your current situation, IT requirements and your future plans. Think about how many network users and ISP (internet service provider) connections you currently have or need. Assess the data output, throughput and security policies you have now, or plan to implement in your network. Accordingly, look for suitable firewall solutions.
- Check if the firewall solution you have in mind is compatible with your existing IT setup.
- Once you get an idea about the firewall model you want, do some research on it. Check its support window and learn about available tech support, security patches and firmware updates. Ensure it’s not a EOL (end of life) model(may have unpatched vulnerabilities).
- Don’t forget about the scalability of the product in your future expansion plans. Like additional bandwidth and users, cloud integration etc.
Myths about firewalls
These are some misconceptions about network firewalls. Let’s clarify them here.
Fundamentally, a firewall is not everything. It’s a part of a cybersecurity architecture. Other security components like IAM (Identity and Access Management), Endpoint Security, Network Security, Data Protection, SOC (Security Operations Center), Incident Response and Recovery, Security Policies & Standards etc are equally important too for a safer IT network.
More rules don’t always equate to more protection. Sometimes, they may restrict genuine network usage. Even create unintentional security gaps in the network.
Example 1- Overlapping or conflicting firewall rules. Lets say, an admin adds a new firewall rule. To block outbound network traffic to a suspicious IP range. But, he forgets about an earlier rule allowing outbound traffic to the same IP range from an app. Firewalls process rules in order. So, if an allow rule already exists, then a block rule later gets bypassed. In the aftermath, an illusion of security was created, leaving a security gap prone to cyber attacks.
Example 2- Excessive deny rules may result in unintended blocking of legit services like DNS (Domain Name System) or NTP (Network Time Protocol). To work around the situation, users or apps may use unauthorized proxies. The result is creation of shadow IT and weak network security.
Cloud-based apps like Google Workspace, Microsoft 365, Zoom etc. are available in public networks. They are prone to cyber attacks, and need firewall protection. Even with a firewall in place, they still need other security controls at cloud edge. Such as Web Application Firewall(WAF), Cloud Access Security Brokers(CASB) and zero trust policies. These measures protect against threats like unauthorized access, API abuse, data exfiltration and lateral movement in the cloud environment.
Final Thoughts
Firewalls remain a cornerstone for network security. They have evolved from simple packet filters to smart cloud-integrated, AI-powered systems. In today’s hybrid and cloud-driven IT environments, firewalls’ role is not just at network perimeter, but within cloud platforms, SD-WAN hubs and micro-segmented workloads.
Choosing the right firewall solution requires clear understanding of your current network demands, security policies, integration needs and future scalability. Pick a firewall that fits your business needs today and scale as you grow. The right firewall solution, configured and maintained effectively, safeguards your network against modern cyber threats.
But remember, firewalls for your IT network should only be a part of a bigger cyber security plan for your business. A plan that includes endpoint protection, identity management, data loss prevention, cloud security and continuous monitoring.
Choose wisely, configure carefully and monitor constantly. And your firewall won’t just protect your network, it’ll empower it.
🔐 Which firewall setup do you use now, or plan to use in your IT network? Got questions or insights? Share them in the comments. Let’s talk cyber security!
