An ACL (Access Control List) is a feature that is used in routers to block or allow traffic based on specific rules or criteria. It can be used to filter traffic based on various parameters, such as the source and destination IP addresses, the protocol being used, or the port number. An ACL is typically used to improve security and control access to a network by allowing only authorized traffic to pass through the router.
A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It is used to prevent unauthorized access to a network and to protect against external threats such as malware or hackers. A firewall can be hardware-based, software-based, or a combination of both.
While an ACL and a firewall both serve to control and protect network traffic, they differ in the way they function and the level of security they provide. An ACL is typically used at the network layer of the OSI model and operates on a smaller scale, while a firewall operates at the application layer and provides a higher level of security.
One similarity between an ACL and a firewall is that they both allow administrators to create and enforce rules to control access to a network. They can both be used to block or allow specific types of traffic, and they both play a role in securing a network against external threats.