Techniques and Tools for Controlling Access, ACL and Firewalls

Network traffic is always increasing in large measure and making the load on routers moving information around more and more difficult, and the quantity of data more and more voluminous. In computing, measures for securing a system are similar and are done through a firewall that allows it to be isolated and for access to be tracked. Access control list allow packets to be filtered following the criteria defined by the user. Filtering function isolates the entity that is to be secured by filtering the entities that access it through the MAC address, IP address, Web address (URL), port number, protocol, etc. Stateful filtering consists of maintaining the context of different sessions in the memory. The chapter presents an example of a physical firewall and two examples of software firewalls.