Firewall

No matter what professional background you might have, it is just enough to get to know the name of the firewall and you will immediately think that there is no joke with such device. Leaving the humor aside, a firewall (see Figure 1.16) is a network device that provides security to the network infrastructure. It does so by controlling and monitoring both incoming and outgoing traffic based on configured security rules. In a nutshell, the firewall to a network infrastructure is like a security officer at an organization's main gate: