. Firewall can be a software or hardware or both which protects our device from external issues.
. It can be Windows Firewall in the Operating system or filtering set in the router.
. Acts as a gatekeeper for all incoming and outgoing traffic.
Software Firewall:
. A software Firewall runs within your computer.
. When your computer is connected to internet, it is necessary to have software firewall which protects from threats.
. Windows has Firewall by default.
. We must ensure that it is enabled.
. If it is not enabled, it is like opening doors of your home and allowing threatful strangers to come in.
. If any device within the network is infected, Software Firewalls protects your computer.
. To enable Windows Firewall, in the control panel Turn on the Windows Firewall.
Hardware Firewall:
. Routers work as Hardware Firewalls.
. Routers use Network Address Translator (NAT) to share common IP from ISP to all the computers in the network.
. Since Software Firewall is present within computer, any virus in computer may effect Software Firewall but not Hardware Firewall which is outside computer.
. It provides security to the entire network of computers.
How does Firewall works?
. Firewall allows you to establish certain rules to determine what traffic should flow in or out of private network.
. Firewall uses any one or combination of the following methods to provide safety:
Packet Filtering:
. Every message we send back and forth is in the form of packets.
. Packets contain information like source and destination IP and ports, data.
. Packet Filtering looks on the ports.
. You can filter on allowing or disallowing traffic from certain ports or IP addresses.
Proxy Server:
. Proxy server allows to send packets from itself hiding all the internal IP addresses.
. Security in this technique is sender and receiver can never see each others ports or IP addresses.
. This allows to reduce attacks from the hackers by hiding internal IP addresses.
Application Gateway:
. It is another sort of Proxy server.
. Computer in a network first establishes connection with Application Gateway.
. It takes care whether to connect destination port or not according to rules it has set.
. Now the communication is through internal Computer-Application Gateway-Destination.
Dynamic Packet Filtering:
. It is slowly replacing all the previous methods.
. It not only checks the header information, but also inbound and outbound data parts.
. It is then compared to the trusted destination source whether or not to allow the data packets from the firewall.