Jacobson, The bsd
packet filter: A new architecture for user-level packet capture, in Proceedings of the USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993 Conference Proceedings.
We modified our polling kernel to implement queue-state feedback (see Section 6.4) from the
packet filter queue.
The remote firewall consists of three major components; the
packet filter, the remote firewall agent, and the remote firewall client agent.
Rather than allowing information from the outside to get sifted through a
packet filter and forwarded into the private network, a system administrator can set up an application gateway, called a proxy server firewall, to prevent the two networks from having any direct contact.
In addition, elmeg T484 features
packet filter firewall, which provides protection against external attacks with preconfigured profiles to protect against the most frequent threats.