Firewall is a hardware or software that protects from intrusions from attackers. It examine all the data packets passing through them to see if they neet the rules defined by the ACL(Access Control List) made by the administration of the network. Firewall also maintain a log of important activities in the network. The log can be configure as per required. It also filters contents on the basis of address, protocol, packet attributes and state.
The types of firewall are as follows:-
Packet filtering firewall
Circuit level gateway firewall
Application level gateway firewall
Stateful multilayer inspection firewall
Packet filtering firewall
Circuit level gateway firewall
Application level gateway firewall
Stateful multilayer inspection firewall
Packet filtering firewall:-
Packet filtering firewalls are deployed on routers which connect the Internet network to Internet. It can be only be implemented on network layer of osi model. It works on the basis of rules defines by Access Control Lists. They check all the packets and screens them against the rules as per the ACL. If the packet is not match the criteria then that packet is dropped and logs are updated. The ACL are created on the basis of address, protocol, packet attributes and state.
Packet filtering firewalls are deployed on routers which connect the Internet network to Internet. It can be only be implemented on network layer of osi model. It works on the basis of rules defines by Access Control Lists. They check all the packets and screens them against the rules as per the ACL. If the packet is not match the criteria then that packet is dropped and logs are updated. The ACL are created on the basis of address, protocol, packet attributes and state.
Circuit level gateway firewall:-
Circuit level gateways are deployed at the session layer of OSIodel and they monitor sessions like TCP three way and handshake to see whether a requested connection is legitimate or not. Major screening happens before the connection is established. Information sent to a computer is secure and appears to be sent from the gateway.
Circuit level gateways are deployed at the session layer of OSIodel and they monitor sessions like TCP three way and handshake to see whether a requested connection is legitimate or not. Major screening happens before the connection is established. Information sent to a computer is secure and appears to be sent from the gateway.
Application level gateway firewall:-
Application level gateways works on the application layer of OSI model and provide protection for specific Application layer protocol. It only works for configured protocols. It can also be configured as Caching servers which in turn increase the network performance and makes it easier to log traffic.
Application level gateways works on the application layer of OSI model and provide protection for specific Application layer protocol. It only works for configured protocols. It can also be configured as Caching servers which in turn increase the network performance and makes it easier to log traffic.
Stateful multilayer inspection firewall:-
Stateful multilayer inspection firewall is combination of all firewalls. They can filter packets at network layer using ACL, check for legitimate sessions on the session layer and thry also evaluate packets on the application layer. They can work on a transparent mode allowing direct connections between the client and the server. It can also implement algorithms and complex security models which are protocol specific, making the connection and data transfer more secure.
Stateful multilayer inspection firewall is combination of all firewalls. They can filter packets at network layer using ACL, check for legitimate sessions on the session layer and thry also evaluate packets on the application layer. They can work on a transparent mode allowing direct connections between the client and the server. It can also implement algorithms and complex security models which are protocol specific, making the connection and data transfer more secure.
No comments:
Post a Comment