Firewall, which means "Firewall" in turkish , is a to control incoming and outgoing network traffic. Firewall can be both hardware-based and software-based. Firewall creates a barrier between trusted networks and untrusted networks. Firewall Lithuania Phone Number List controls access to network resources through a positive contro Lithuania Phone Number List model. Thus, depending on the firewall policy, some network traffic is allowed and all other traffic is denied. Firewall Lithuania Phone Number List types and its history firewalls are barriers created to prevent problems from leaking and spreading. Controlling server access became a priority as large organizations began to move from legacy systems to a client-server model. Before firewall, that is, in the late 1980s, acls, or access control lists, were used to ensure network security. Access control lists only determined which ip addresses were or weren't allowed to access the network. With the spread of the internet, it has become clear that such filtering Is insufficient to block malicious traffic. Therefore, new ventures were needed and in 1992 digital equipment corp. Announced dec seal, the first commercial firewall. Along with this initiative, firewall technology also showed regular developments, just like cyber attacks.Packet filtering firewallsold firewalls used to work like a packet filter, Lithuania Phone Number List examining exchanges between online computers. During Lithuania Phone Number List a packet exchange, predetermined information such as source and destination address, protocol and port number were checked. Unauthorized packets, on the other hand, were removed without being routed directly to their destination. For example; if a packet is configured with a rule to prevent organization x from accessing it, packets from organization x will be removed from port.Packet filtering firewalls; although it is used to obtain resources and port numbers, it operates on the first 3 layers of the osi reference model, physics, data link, and networking. While it's usually a fast and efficient way They don't have the ability to tell if a package is part of the current traffic flow. As they handle each packet separately, they make them vulnerable to cyber attacks.Cyber-offensivestateful firewallto identify the status of a connection, a packet Lithuania Phone Number List must have enough information to evaluate whether it is a new connection or part of another existing connection, so firewalls need to log all connections. This is called a stateful Lithuania Phone Number List firewall. Stateful firewall was first introduced by check point software in 1994 and became a common feature of all firewalls in the late 1990s.This additional information can be used to speed up the process of granting or denying access based on the history of a packet in the status table. This way, no more unnecessary analysis is done to packages that are part of existing packages. If a package is not related to existing packages, it is re-evaluated according to established