The firewall can simply examine the IP address or domain name from which the packet was sent and determine whether to allow or deny the traffic. This device is often called a packet-filtering router.īy comparing the source addresses of these packets with an access list specifying the firewall’s security policy, the router determines whether to forward the packets to their intended destinations or stop them.

In its simplest form, a firewall is essentially a kind of router or computer with two network interface cards that filters incoming network packets. In today’s networking environment in which corporate networks are connected to the Internet – inviting hackers to attempt unauthorized access to valuable business information – a corporate firewall is essential. More generally, a firewall is any system that controls communication between two networks. Firewalls are usually dedicated machines running at the gateway point between your local network and the outside world, and are used to control who has access to your private corporate network from the outside – for example, over the Internet.

We call a Firewall to any system or device that allows safe network traffic to pass while restricting or denying unsafe traffic. Definition of FIREWALL in Network Encyclopedia.

What is firewall in networking