Tulemüürifunktsioone

Tulemüürifunktsioone refers to the various capabilities and operations that a firewall can perform to control network traffic. The primary function of a firewall is to act as a barrier between a trusted internal network and untrusted external networks, such as the internet. This is achieved by examining incoming and outgoing network packets and deciding whether to allow or block them based on a predefined set of security rules.

A fundamental tulemüürifunktsioone is packet filtering, where firewalls inspect individual packets for specific criteria like source and destination IP addresses, port numbers, and protocols. Stateful packet inspection is a more advanced form, where the firewall keeps track of the state of active network connections. This allows it to make more intelligent decisions about whether a packet is part of a legitimate existing session.

Another key tulemüürifunktsioone is the ability to perform network address translation (NAT). NAT allows multiple devices on a private network to share a single public IP address, which helps conserve IP addresses and adds a layer of security by hiding the internal network structure.

Application-level gateways, also known as proxy firewalls, offer even deeper inspection capabilities. They understand specific application protocols (like HTTP or FTP) and can inspect the content of traffic for malicious code or policy violations. More modern firewalls also incorporate intrusion detection and prevention systems (IDPS), which monitor network traffic for suspicious patterns that might indicate an attack and can take action to block them. Finally, firewalls can also be configured to log network activity, providing valuable data for security analysis and troubleshooting.