Firewall
A firewall is a security device/system (hardware or software) that can help protect your network by filtering traffic and blocking outsiders from gaining unauthorized access to the private data on your computer.
Firewall Types
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Packet-filtering
This is the most basic firewall type. In other words, it provides only basic protection.
Packet filtering firewalls don’t open data packets to inspect their contents. Any data packet that fails the simple inspection is dropped.
They are not resource-intensive and have a low impact on system performance.
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Proxy
Proxy firewalls filter network traffic at the application layer of the OSI network model.
These firewalls typically operate in the cloud or through another proxy device. Instead of allowing traffic to connect directly, a connection to the traffic’s source is established and the data packet is inspected.
They are relatively slow.
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Network Address Translation (NAT)
These firewalls work by assigning a public address to a group of devices inside a private network. With NAT, individual IP addresses are hidden. Therefore, attackers scanning for IP addresses on a network are prevented from discovering specific details.
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Web Application (WAF)
WAF are responsible for
- filtering
- monitoring
- blocking
data packets as they travel in and out of websites or web applications.
A WAF is most similar to the proxy firewall, but has a more specific focus on defending against application layer web-based attackers.
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Next-Gen (NGFW)
NGFW is the most popular firewall type.
These firewalls provide extensive application control and visibility, distinguish between safe and dangerous applications, and block malware from entering a network.