Firewall provide security system in our network. there is two type of firewall hardware firewall and software firewall it is used to prevent unauthorized accessing in network from outside and internal network. if any unauthorized user want communicate between the network then firewall prevent network from that user.
Firewall is a Software program which used to proctect out computer from Virus , trojen , Worm and also from Hackers. Its prevent our computer from hackers when we are using Internet.
Main objective of firewall
- What should come in the intranet(Inbound traffic)
- What should come out on the intranet(outbound traffic)
Type of Firewall
1. Software Firewall – Now days many operating system comes with Inbuilt Firewall which used to protect your computer from unauthorized accessing from Hackers.
2. Hardware Firewall – Hardware firewall used in the Network, Its work between our computer network and the Internet. Its control the Incoming and outgoing traffic according to our configuration. Hardware firewall just like Router and Switch and also its inbuilt with router and switch.
There are many type of Firewall Technique Explain below
1. Packet Filtering
Packet filtering firewall watching incoming and outgoing packet in the Network . It will prevent to unwanted packet to enter to the Network based user define that which Incoming and Outgoing Packet you have blocked.
Each packet examine by the firewall if packet match with filtering Rule then packet will be reject.
2. Stateful Firewall
Stateful firewall work on the Transport layer of the OSI Model . Stateful firewall is remember the already establish connection in your network. Firewall management can do setting only already establish connection can be transfer and receive packets.
3. Proxy Firewall
Proxy Firewall act like a mediator between network client Computer and the Internet. Proxy provide the Internet connectivity to the Client Computer. Proxy Firewall firstly inspect content then it provide access to the base on setup on proxy server. Proxy Firewall filter, Cache and log which is coming from the client to keep the network secure. Its used to control outbound traffic .