Business PME is a gate of free information bound for the companies in the United States of America. This website offers thousands of contents as well as a companies directory.
The group’s other BtoB websites
-- Professional Networking
Saturday March 13th 2010
Searcharticles Search
companies
- Strategy
- Marketing
- Advertising
- Trade
- Human Ress.
- Law & Rights
- Economics
- Finance
- Production
- Technologies
Firewall | ||
A firewall is an information technology (IT) security device which is configured to permit, deny or proxy data connections set and configured by the organization's security policy. Firewalls can either be hardware and/or software based. A firewall's basic task is to control traffic between computer networks with different zones of trust. Typical examples are the Internet which is a zone with no trust and an internal network which is (and should be) a zone with high trust. The ultimate goal is to provide controlled interfaces between zones of differing trust levels through the enforcement of a security policy and connectivity model based on the least privilege principle and separation of duties. A firewall is also called a Border Protection Device (BPD) in certain military contexts where a firewall separates networks by creating perimeter networks in a DMZ. In a BSD context they are also known as a packet filter. A firewall's function is analogous to firewalls in building construction. Proper configuration of firewalls demands skill from the firewall administrator. It requires considerable understanding of network protocols and of computer security. Small mistakes can render a firewall worthless as a security tool. TypesThere are three basic types of firewalls depending on: * Whether the communication is being done between a single node and the network, or between two or more networks. * Whether the communication is intercepted at the network layer, or at the application layer. * Whether the communication state is being tracked at the firewall or not. With regard to the scope of filtered communications there exist...* Personal firewalls, a software application which normally filters traffic entering or leaving a single computer. * Network firewalls, normally running on a dedicated network device or computer positioned on the boundary of two or more networks or DMZs (demilitarized zones). Such a firewall filters all traffic entering or leaving the connected networks. The latter definition corresponds to the conventional, traditional meaning of "firewall" in networking. In reference to the layers where the traffic can be intercepted, three main categories of firewalls exist: * Network layer firewalls. An example would be iptables. * Application layer firewalls. An example would be TCP Wrappers. * Application firewalls. An example would be restricting ftp services through /etc/ftpaccess file These network-layer and application-layer types of firewall may overlap, even though the personal firewall does not serve a network; indeed, single systems have implemented both together. There's also the notion of application firewalls which are sometimes used during wide area network (WAN) networking on the world-wide web and govern the system software. An extended description would place them lower than application layer firewalls, indeed at the Operating System layer, and could alternately be called operating system firewalls. Lastly, depending on whether the firewalls keeps track of the state of network connections or treats each packet in isolation, two additional categories of firewalls exist: * Stateful firewalls * Stateless firewalls Copyright 2008 - France BtoB from Wikipédia
|
• Freeware
• Data mining • The Nature of Software engineering • Product development processes and method&hellip • ADSL in France • ARM Holdings Company • Data (computing) | |
