[ Pobierz całość w formacie PDF ]
.tions in response to a transmission from one A brouter can route one or more specificworkstation.protocols, such as TCP/IP, and bridge all53Copyright © 2000 SYBEX Inc., Alameda, CA.www.sybex.com 2461book Page 54 Thursday, May 4, 2000 11:59 AMbrownoutothers, for example, and can operate at ei- See also denial of service attack; dictionaryther the data-link layer or the network layer attack; social engineering; Trojan Horse.of the OSI Reference Model.BSD Unix See Berkeley Software Distri-See also gateway.bution Unix.BSOD See blue screen of death.brownout A short period of low volt-age, often the result of an unusually heavybuffer An area of memory set aside fordemand for power, that may cause yourtemporary storage of data.Often, the datacomputer to crash.If your area experienc-remains in the buffer until some externales frequent brownouts, consider using aevent finishes.A buffer can compensate forUPS (uninterruptible power supply) as athe differences in transmission or process-battery backup system.ing speed between two devices or between acomputer and a peripheral device, such as abrowse list A list of computers and ser-printer.vices available on a network.Buffers are implemented in a variety of ways,browser 1.An application program usedincluding first-in-first-out (FIFO) used forto explore Internet resources.A browser letspipes and last-in-last-out used for stacks andyou wander from Web site to Web site with-circular buffers such as event logs.out concern for the technical details of theSee also pipe.links between them or the specific methodsused to access them and presents the infor-buffered repeater Any device that am-mation text, graphics, sound, or video asplifies and retransmits a signal so that it cana document on the screen.travel greater distances.A buffered repeatercan also control the flow of information to2.A small application used to scan a data-prevent collisions.base or a list of files.See also repeater.3.In Windows NT networking, a mecha-nism used as a name service.bug A logical or programming error inSee also Web browser; World Wide Web.hardware or software that causes a mal-function of some sort.If the problem is inbrute-force attack A technique em- software, it can be fixed by changes to theployed by intruders that checks every pass- program.If the fault is in hardware, newword in a password file against every circuits must be designed and constructed.possible password generated sequentially.Some bugs are fatal and may cause a pro-A brute-force attack is very clumsy, is usu- gram to stop responding or cause data loss,ally considered the last resort in an attack, others are just annoying, and many are nottakes a long time to run, and is easily de- even noticeable.The term apparently orig-tected by even the most modest security pre- inates from the days of the first electrome-cautions.Also called a keyspace attack.chanical computers, when a problem was54Copyright © 2000 SYBEX Inc., Alameda, CA.www.sybex.com 2461book Page 55 Thursday, May 4, 2000 11:59 AMbus masteringtraced to a moth caught between two con- of the interface card, which ensures that ev-tacts inside the machinery.ery card has a unique address.See also hardware address.See also bug fix.burst mode A method of data transmis-bug fix A release of hardware or soft-sion in which information is collected andware that corrects known bugs but does notthen sent in one single high-speed transmis-contain new features.Such releases are usu-sion, rather than one packet or character atally designated by an increase in the decimala time.portion of the revision number; for exam-ple, the revision level may advance from 2.0Systems that use multiplexers to serve sever-to 2.01 or 2.1, rather than from 2.0 to 3.al channels often use burst mode to serviceeach channel in turn.Much LAN traffic canbuilt-in groups The default groups pro-be considered burst mode transmission: longvided with some operating systems that de-periods of inactivity punctuated by shortfine a collection of rights and permissionsbursts of intense activity.In Novell Net-for members.Using built-in groups is anWare, burst mode is known as packet burst.easy way of providing access to commonlyused network resources.bus An electronic pathway along whichsignals are sent from one part of a computerbulletin board system Abbreviatedto another.A PC contains several buses,BBS.A computer system equipped with oneeach used for a different purpose:or more modems, serving as a message-passing system or centralized information The address bus allocates memorysource, usually for a particular special in- addresses.terest group.Bulletin board systems wereThe data bus carries data between the pro-often established by software vendors andcessor and memory.by PC user groups in the past, but have beenThe control bus carries signals from thereplaced in recent times by Web sites.control unit.bundled software Programs combinedSee also architecture; Extended Industryinto a single package sold for a single price.Standard Architecture; Industry StandardSales aimed at a specific target, such as theArchitecture; local bus; Microchannelmedical profession, usually bundle hard-Architecture; Peripheral Componentware with application-specific softwareInterconnect local bus.suited to that profession.See also unbundled software.bus mastering A technique that allowscertain advanced bus architectures to dele-burned-in address The hardware ad- gate control of data transfers between thedress on a network interface card (NIC).CPU and associated peripheral devices to anThis address is assigned by the manufacturer add-in board.This technique gives network55Copyright © 2000 SYBEX Inc., Alameda, CA.www.sybex
[ Pobierz całość w formacie PDF ]