What is Firewall?
A firewall acts as a security barrier between a trusted internal network and an untrusted external network, typically the internet. It monitors incoming and outgoing network traffic, filtering data packets based on predefined security rules. Firewalls essentially act as security guards, checking the legitimacy of traffic before allowing it to pass through. This helps to prevent unauthorised access, malicious attacks and data breaches.
Benefits_
- Enhanced network security: Firewalls act as a first line of defence, blocking unauthorised access attempts and preventing malware or other threats from infiltrating the internal network.
- Data protection: Firewalls can restrict the flow of sensitive data out of the network, helping to prevent data leaks and unauthorised access to confidential information.
- Improved application control: Firewalls can control which applications are allowed to access the internet, preventing unauthorised applications from transmitting data or posing security risks.
- Reduced risk of network intrusions: By filtering traffic based on pre-defined rules, firewalls make it more difficult for attackers to gain access to the network and launch cyber attacks.
Use cases_
- Securing business networks: Firewalls are essential for organisations of all sizes to protect their internal networks from cyber attacks and data breaches.
- Safeguarding personal devices: Firewalls can be implemented on personal computers and home networks to provide a basic layer of security against malware and unauthorised access attempts.
- Public Wi-Fi protection: When using public Wi-Fi networks, firewalls can help mitigate security risks by restricting data transmission and potential exposure to malicious actors.
- Segmenting networks: Firewalls can be used to segment internal networks, creating isolated zones for different departments or functions, improving overall security posture.
Key components_
- Packet filtering: Analyses data packets based on pre-defined rules, such as source and destination IP addresses, ports and protocols, allowing or blocking traffic accordingly.
- Stateful inspection: Tracks the state of network connections and filters traffic based on established connections, providing a more granular level of control.
- Proxy services: Can act as an intermediary between internal devices and the internet, filtering traffic and hiding internal IP addresses from external threats.
- Application control: Allows for granular control over which applications are permitted to access the internet, mitigating risks associated with unauthorised applications.
Microsoft offers several firewall solutions that integrate seamlessly with other Microsoft security products:
- Windows Defender Firewall: A built-in firewall included within Windows operating systems, providing basic protection for personal devices.
- Azure Firewall: A cloud-based firewall service that offers advanced threat protection and secure application access for organisations using Microsoft Azure cloud services.
- Microsoft Defender for Endpoint with Firewall Management: Integrates endpoint protection with firewall management capabilities, offering a unified solution for securing devices and network traffic.
