Host-based firewalls run on host computers and control network traffic in and out of those types of firewalls in network security pdf. The term was applied in the late 1980s to network technology that emerged when the Internet was fairly new in terms of its global use and connectivity.
The predecessors to firewalls for network security were the routers used in the late 1980s. The firewall shows its settings for incoming and outgoing traffic. The first reported type of network firewall is called a packet filter. This fairly basic system is the first generation of what later became a highly involved and technical Internet security feature.
Packet filters act by inspecting packets which transfer between computers on the Internet. Conversely, when a packet matches one or more programmed filter rules, it is allowed to pass. This is achieved by retaining packets until enough information is available to make a judgement about its state. In June 1994, Wei Xu extended the FWTK with the kernel enhancement of IP filter and socket transparent.