Firewall

• Firewall is used to block the unwanted files or packets which are entering into the trusted network.
• Firewall protects from the hackers.
• Firewalls are available in two ways:
• Hardware Firewall
• Software Firewall
• Firewalls allows or block the data based on the access list created by it.

Hardware Firewall:

• It is a physical device which is used as barrier between local network and public network(i.e, world).
• It secures each Host or PC in the network.
• It is available in two types:
• Firewall Networking Device
• Inbuilt Firewall in Modern Router

Software Firewall:

• It is an application available in all Windows OS and some trusted software companies.
• It blocks any malicious entering into that single PC or Host.
• Software Firewall helps in protecting the remaining in network.

Types of Firewall Devices:

Packet Filtering Firewall:

• When ever packet comes it checks the Senders and Receivers IP and Port No.
• Checks the details using access control list.
• This fast way of the accessing.
• Draw back is it never checks the data portion in the packet.

Application/Proxy Firewall:

• Blocks the user identity to the public network.
• Proxy Firewall Working
• When ever user requests for any site.
• Firewall receives the information and requests the public server as it is requesting firewall.
• Public server understands that request is send by the firewall not by user in it.
• Checks with the data packets in the network.

Hybrid Firewall:

• Hybrid Firewall it is combination of the Proxy and Packet Firewall.
• Packet which is coming is first pass through Proxy and then by the Packet Firewall.