What is a firewall and how does it protect against hacking attacks?

A firewall is a network security device that acts as a barrier between an internal network and external networks, such as the internet. It monitors and controls incoming and outgoing network traffic based on predetermined security rules.

Firewalls protect against hacking attacks by implementing various security measures. Firstly, they examine all incoming and outgoing network packets, analyzing their source, destination, and content. This inspection helps identify and block any malicious or unauthorized traffic.

Firewalls also use access control lists (ACLs) to determine which network traffic is allowed or denied based on specific criteria, such as IP addresses, ports, or protocols. By configuring these rules, firewalls can restrict access to sensitive resources and prevent unauthorized connections.

Furthermore, firewalls can employ stateful packet inspection (SPI) to track the state of network connections. This means that they can differentiate between legitimate packets belonging to an established connection and suspicious packets attempting to initiate a new connection. By monitoring the state of connections, firewalls can detect and block unauthorized attempts to establish connections from external sources.

Firewalls can also provide network address translation (NAT) functionality, which hides the internal IP addresses of devices on the network. This helps protect against hacking attacks by making it more difficult for attackers to identify and target specific devices.

Additionally, firewalls can be configured to log network activity, allowing administrators to monitor and analyze potential security incidents. This logging capability helps in identifying patterns or anomalies that may indicate a hacking attempt or a security breach.

In summary, firewalls act as a first line of defense against hacking attacks by monitoring and controlling network traffic, implementing access control rules, employing stateful packet inspection, providing NAT functionality, and enabling logging for security analysis.