| firewall |
| A method for implementing security policies
designed to keep a network secure from intruders. It can be a single router that filters
out unwanted packets or may comprise a combination of routers and servers each performing
some type of firewall processing. Firewalls are widely used to give users secure access to
the Internet as well as to separate a company's public Web server from its internal
network. Firewalls are also used to keep internal network segments secure; for example,
the accounting network might be vulnerable to snooping from within the enterprise. In
practice, many firewalls have default settings that provide little or no security unless
specific policies are implemented by trained personnel. Firewalls installed to protect entire networks are typically implemented in hardware; however, software firewalls are also available to protect individual workstations from attack. While much effort has been made excluding unwanted input to the internal network, less attention has been paid to monitoring what goes out. Spyware are applications that keep track of your habits and send those statistics to a Web site (see spyware). Following are the techniques used in combination to provide firewall protection. See firewall appliance and honeypot. Packet Filter Blocks traffic based on a specific Web address (IP address) or type of application (e-mail, ftp, Web, etc.), which is specified by port number. Also known as a "screening router." Proxy Server Serves as a relay between two networks, breaking the connection between the two. Also typically caches Web pages (see proxy server). Network Address Translation (NAT) Allows one IP address, which is shown to the outside world, to refer to many IP addresses internally; one on each client station. Performs the translation back and forth. Stateful Inspection Tracks the transaction to ensure that inbound packets were requested by the user. Generally can examine multiple layers of the protocol stack, including the data, if required, so blocking can be made at any layer or depth.   |
| firewall appliance |
| A device that provides firewall protection for a network. It includes all the necessary hardware and software in a self-contained package that plugs in between the two networks being isolated. Most firewall appliances are entirely solid state and include a stripped down operating system kernel, making the entire system less vulnerable to head crashes and other failures. See firewall. |
| FireWire |
| A high-speed serial bus developed by Apple and
Texas Instruments that allows for the connection of up to 63 devices. Also known as the
IEEE 1394 standard, the i.Link connector and the High Performance Serial Bus (HPSB), the
original spec calls for 100, 200 and 400 Mbits/sec transfer rates. IEEE 1394b provides
800, 1600 and 3200 Mbits/sec speeds. FireWire supports hot swapping, multiple speeds on the same bus and isochronous data transfer, which guarantees bandwidth for multimedia operations. It is expected to be widely used for attaching digital cameras and other video devices to the computer. See Tailgate.  |
| firmware |
| A category of memory chips that hold their content without electrical power and include ROM, PROM, EPROM and EEPROM technologies. Firmware becomes "hard software" when holding program code. |
| FLOPS |
| (FLoating point Operations Per Second) The measurement of floating point calculations. For example, 100 megaflops (mflops) is 100 million floating point operations per second. |