The most basic form of firewall functionality, involving the ability to examine each packet to determine its IP address, and to accept or reject it based on this information. Vulnerable to IP spoofing and to fragmented IP information.
Ability to prevent certain types of network packets from going from one network to another. This can be employed for security reasons (to prevent access from unauthorized users) or to improve performance by disallowing unnecessary packets from going over a slow connection.
Discarding unwanted network traffic based on its originating address or range of addresses or its type (e-mail, file transfer, etc.). Packet filtering is generally performed in a router.
A type of firewall that, although fast, has little intelligence. This reduces its effectiveness and flexibility. It is a powerful tool when used in conjunction with other types of Firewall - Stateful inspection and Application Proxy.
the process of examining and deciding whether to forward or discard data packets on a network. For example, a packet filter in a network router might be used to discard packets from the Internet to a particular UniSA system in order to protect it from security attacks.
A second layer of filtering on top of the standard filtering provided by a traditional transparent bridge. Can improve network performance, provide additional security, or logically segment a network to support virtual workgroups.
Prevents certain types of network packets from either being sent or received. This can be employed for security reasons (to prevent access from unauthorized users) or to improve performance by disallowing unnecessary packets from going over a slow connection. See also packet.
The ability to selectively allow only certain network IP packets through a server or router. This is done to restrict access from the Internet into a computer or LAN, or from a LAN out to the Internet.
A type of service filtering to permit or deny network traffic based on the data source, destination, service or protocol of the data packets.
A security measure that rejects packets from unauthorized ports, hosts, and IP addresses.
The action a device takes to selectively control the flow of data to and from a network. Packet filters allow or block packets, usually while routing them from one network to another (most often from the Internet to an internal network, and vice-versa). To accomplish packet filtering, you set up rules that specify what types of packets (those to or from a particular IP address or port) are to be allowed and what types are to be blocked.
A feature incorporated into routers and bridges to limit the flow of information based on predetermined communications such as source, destination, or type of service being provided by the network. Packet filters let the administrator limit protocol specific traffic to one network segment, isolate e-mail domains, and perform many other traffic control functions.
The capability of performing a packet-by-packet inspection of all routable traffic.
Controlling access to a network by analyzing the headers of incoming and outgoing packets, and letting them pass or halting them based on rules created by a network administrator. A packet filter allows or denies packets depending on where they are going, from whom they are sent, or what port they use. Packet filtering is one technique, among many, for implementing security firewalls.