How Firewall Protection Works
As the internet is not a very safe medium now a day’s, a person has to work for the security of his personal information from strangers and hackers and use various software for this purpose. Firewall is one of this software. Firewall basically guards computers linked in a network from deliberate adverse interference that could corrupt your data or malfunction your computer services. Firewall protects your PC by blocking some certain types of traffic between the destination and the source.
All network traffics consists of three things a source, a protocol and a destination. These protocols are mostly TCP, ICMP or UDP. In the case of TCP and UDP there is a source port and a destination port. Usually destination port is a well recognized port and a source port is taken at random and is a random port. On the other hand if the protocol is ICMP then an ICMP message types comes into operation. Echo replay and Echo request are two of the most general ICMP message types.
Firewall basically asks the user which protocol he wants to allow and which to deny. Mostly firewalls deny all the inbound traffic to all internal IP addresses. Now a day’s firewalls allow packets, which are basically responses to out bound traffic, to enter the network. Inbound restriction is the core security feature given by the firewalls.
Some of the network security administrators want to deny outbound traffic. This is a method of restricting a user to using only approved protocols and protect them from using unapproved or rejected protocols. This limits a user from sending outbound mails or from using online chat systems. Outbound limitations are mostly exposable to works-arounds and these limitation works completely as premeditated. Firewall is useful and efficient way of protecting your PC and is very popular for that.