what is a network firewall?
A firewall is a network security device that monitors incoming and outgoing network traffic and allows or blocks data packets based on a set of security rules. The goal is to create a barrier between your internal network and external traffic (such as the internet) to prevent malicious traffic, such as viruses and hackers.
how does a network firewall work?
Basically, network firewalls use four mechanisms to limit traffic. A device or application can use more than one to provide in-depth protection. The four mechanisms are packet filtering, circuit-level gateway, proxy server, and application gateway.
what are the 3 types of network firewalls?
Type 1: network-based firewalls
A network-based firewall directs traffic from one network to another.
With a network-based firewall, TCP / IP protocol stack packets can pass through the firewall through a defined set of rules. Often, these network rules are: default rules in a list or an administrator can override these rules, change what can be transmitted or rejected.
Type 2: application firewall
An application firewall works with the TCP / IP stack.
In basic words: an application’s firewall can intercept all packets that travel to or from an application.
If the firewall believes that a package is not needed or contains harmful content, the package is removed. With limitations for computer worms, application firewalls add an additional layer to packages that travel to their destination.
Type 3: proxy server
A proxy server responds to incoming packets and blocks other packets. A proxy server can be assigned on a hardware device or as a software.
A proxy server acts as an access point from one network to another on behalf of the user. This makes it difficult to enter an internal system from the external network.
Proxy server firewalls can mask the IP address and limit different types of traffic. They are aware of the protocol and offer a security analysis.
network firewall software
7 The best network firewall software
SolarWinds Network Security Event Manager (FREE TRIAL) A SIEM solution with real-time firewall management and automated change management.
Zscaler Cloud Firewall Next-generation cloud-based firewall with SSL inspection, detailed firewall policy and real-time monitoring.
Barracuda CloudGen Cloud-based Firewall Firewall that can detect zero-day threats, with monitoring of network activity and assigning VPN tasks.
GFI Languard Kerio Control Network Firewall with a theft prevention system, deep packet inspection, configurable traffic policy, and usage reports.
pFSense Open Source network Firewall that can be installed on any hardware and comes with a web-based GUI with add-ons.
IPFire open-source network firewall with an intrusion prevention system, warnings, inspection of packages with status and add-ons.
SophosXG Firewall Next-generation Firewall with dashboard, automatic threat response, sandboxing and SSL inspection.
best firewall devices to protect your home network
Bitdefender BOX 2 (recommended)
Ubiquiti Unifi Security Gateway