A firewall is a security measure that is designed to provide protection to an information system or any networked computer that has sensitive information on the inside and needs to restrict the information that flows in and out of the system. With a firewall, all the traffic that gets into the network will be scanned and filtered for any errors as well as filtering the IP addresses that are gaining access to the system. The firewall is a safety measure and a security mechanism that makes sure that all the information that is getting into and out of a networked system is scanned for any malware before getting allowed to pass through.
A firewall is made up of a filter and an access rules list which work with one another to ensure that all the incoming traffic to the network is filtered before getting into the system. The firewall, for instance, will be able to keep a list of which IP addresses are allowed to make incoming connections and which addresses are restricted from getting into the network. This is very simple to carry out and the access list makes sure that anyone that tries to get into the network has the proper credentials for getting into the network. Otherwise, the firewall will lock them out of the network and prevent them from getting into the system.
Another feature of the firewall is the ability to detect which streams of traffic are legal and which ones are somewhat suspicious. The traffic streams that seem illegal to the firewall will be detected and traced down to where they originate from. If the IP address the traffic comes from is not legal, then the connections will be cut off and prevented from getting into the system as per the rules of the firewall. A simple firewall is also able to maintain a memory of the patterns of access attempts and what kind of traffic has been getting into the system and this makes sure that all information getting into and out of the system is scanned before passing through.
With a firewall, the information that is within a system will not be accessible from outside unless the party trying to access the information has got the proper authentication information in order to verify their identities to the information system. Otherwise, they will be denied access from the system and will not be able to get past the firewall.
Nothing can get past the firewall no matter how cleverly it is concealed and the rules keep updating for the firewall to identify parties that have been trying to enter the system illegally and which ones have got the proper authentication to get into the system. All connections are also scanned and the system is able to filter through the traffic getting into and out of the system in order to make sure that nothing bad is able to penetrate the firewall and infect the system. In other words, the firewall is the best protective measure for modern information systems.