Network+ 2005 Key Terms & Info (Part Iii)

Front 1

Classful Addressing

Back 1

Simplest type of IP addressing as only Class A, Class B and Class C addresses are recognized. Class A: IP Address = 8 bits, Host = 24 bits; Class B: IP Address = 16 bits, Host = 16 bits; Class C: IP Address = 24 bits, Host = 8 bits.

Front 2

Network ID

Back 2

The terms network number and network prefix are used interchangeably.

Front 3

Subnet Mask

Back 3

Use of subnet masks identify how a network is subdivided. "1" bits in a subnet mask indicate that corresponding bits in an IP address contain network information. "0" bits indicate that corresponding bits in an IP address contain host information

Front 4

ANDing

Back 4

Logical process of combining bits. "1" bits plus "1" bits result in a "1". "0" bit plus any other bit results in a "0".

Front 5

Reserved IP Addresses

Back 5

IP addresses ending in "0" are reserved for the network ID (Example: 199.34.89.0 is invalid). IP addressing ending in "255" are reserved for the broadcast address (Example: 199.34.89.255 is invalid).

Front 6

Equation for Calculating Subnets

Back 6

2 to the nth power - 2 = y n = the number of bits in the subnet mask that must be switched from 0 to 1; y = the number of subners that result.

Front 7

Extended Network Prefix

Back 7

Term used to describe the additional bits used for subnet information plus the existing network ID.

Front 8

Supernet

Back 8

Subnet created by moving the subnet boundary to the left.

Front 9

CIDR Notation (Slash Notation)

Back 9

New shorthand for denoting the position of subnet boundaries (using a forward slash). Example: 199.34.89.0/22

Front 10

CIDR Block

Back 10

Forward slash plus the number of bits used for the extended network prefix. Example: 199.34.89.0/22

Front 11

Default Gateway

Back 11

First interprets its outbound requests to other subnets, and then interprets its inbound request from other subnets. Every device on a TCP/IP based network has one.

Front 12

Default Router

Back 12

Default gateways can also be a network interface on a router. Internet gateways are usually assigned an IP address that ends with an octet of "1".

Front 13

Core Gateways

Back 13

Gateways that make up the Internet backbone.

Front 14

Intranet

Back 14

Network or part of a network that uses browser-based services to exchange information within an enterprise.

Front 15

Extranet

Back 15

Network that uses Internet-like services and protocols to exchange information within an organization and with certain, authorized users outside of that organization.

Front 16

Convergence

Back 16

The provision of data, voice, fax and video services over the same packet-switched network.

Front 17

Toll Bypass

Back 17

Use of VoIP to avoid paying long distance telephone charges.

Front 18

IP Telephony

Back 18

Another name for VoIP (Voice over IP).

Front 19

IP Telephones

Back 19

Used with VoIP to transmit and receive only digital signals.

Front 20

Softphone

Back 20

Use of a computer programmed to act like an IP telephone.

Front 21

Call Tracking System

Back 21

Software program (also known as help disk software) that provides a user-friendly graphical interface that prompts the user for every piece of information associated with the problem: unique number, call info, nature of problem, time to resolve, and nature of resolution.

Front 22

Supported Services List

Back 22

Document that lists every service and software package supported within the organization, plus the names of first- and second-level contacts for those services or software packages.

Front 23

Change Management System

Back 23

Process or program that provices support personnel with a centralized means of documenting changes to a network.

Front 24

Tone Generator

Back 24

Small electronic device that issues a signal on a wire pair. Used with a tone locator, which emits a tone when it detects electrical activity on a wire pair.

Front 25

Multimeter

Back 25

Instrument that measures many characteristics of an electric circuit, including its resistance and voltage.

Front 26

Voltmeter

Back 26

Instrument that measures the pressure, or voltage, of an electric current.

Front 27

Ohmmeter

Back 27

Device used to measure resistance.

Front 28

Cable Tester

Back 28

Also called cable checkers or continuity testers, it finds the cause of a problem by simply testing whether your cable is carrying a signal to its destination. Also includes more sophisticated tools that can measure cable performance.

Front 29

Cable Performance Tester

Back 29

Accomplishes the same continuity and fault tests as a cable tester, but can also: measure distance to connectivity device; measure attenuation; measure crosstalk; test cable standards.

Front 30

Network Monitor

Back 30

Software-based tool that continually monitors network traffic from a server or workstation attached to a network - layer 3 of the OSI. Ships with Windows NT, 2000 and 2003.

Front 31

Promiscuous Mode

Back 31

Device driver that directs the NIC to pick up all frames that pass over the internet - not just those destined for the node served by the NIC.

Front 32

Baseline

Back 32

Record of how the network operates under normal conditions, including its performance, collision rate, utilization rate, etc.

Front 33

Runts

Back 33

Packets that are smaller than the mediums minimum packet size. Runts often the result of collisions.

Front 34

Giants

Back 34

Packets that exceed the mediums maximum packet size.

Front 35

Jabber

Back 35

Device that handles electrical signals improperly, usually affecting the rest of the network - usually the result of a bad NIC.

Front 36

Ghosts

Back 36

Frames that are not actually data frames, but aberrations caused by a device misinterpreting stray voltage on the wire - ghosts contain no starting delimeter.

Front 37

Protocol Analyzer

Back 37

Tool to capture network traffic and analyze frames - all the way up to Layer 7 of the OSI. It supports a multitude of protocols and network topologies. Hardware-based protocol analyzer is called a "sniffer".

Front 38

Spectrum Analyzer

Back 38

Tool that can assess the quality of the wireless signal.

Front 39

Site Selection

Back 39

Determining the optimal placement for Access Points on a wireless LAN.

Front 40

Polymorphic Viruses

Back 40

Viruses that change their characteristics (bytes, size and internal instructions.

Front 41

Time-dependent Viruses

Back 41

Programmed to activate on a particular date (also known as time bombs) - can remain dormant and harmless until their activation date arrives.

Front 42

Signiture Scanning

Back 42

Comparison of file's content with known virus signitures - database must be frequently updated so that the software can detect new viruses as they emerge.

Front 43

Integrity Checking

Back 43

Method of comparing current characteristics of files and disks against an archived version of these charatcteristics to discover any changes - involves using a checksum.

Front 44

Heuristic Scanning

Back 44

Scanning techniques that attempt to identify viruses by discovering "virus-like" behavior.

Front 45

Network Failure

Back 45

Deviation from a specified level of system performance for a given period of time.

Front 46

Network Fault

Back 46

Involves the malfunction of one component of a system, which can result in a failure.

Front 47

Standby UPS (Uninterruptible Power Supply)

Back 47

Provides continuous voltage to a device by switching virtually instantaneously to the battery when it detects a loss of power (also called offline UPS).

Front 48

Online UPS (Uninterruptible Power Supply)

Back 48

Uses the A/C power from the wall to continuously charge its battery, while providing power to a network device through its battery.

Front 49

Volt-amp (VA)

Back 49

To determine approximately how many VAs your device requires, use this conversion: 1.4 volt-amps + 1 Watt (Example: 200W power supply would need a UPS capable of at least 280 VA).

Front 50

Fail-over

Back 50

Capability of a component to immediately assume the duties of an identical component should the original fail.

Front 51

Load Balancing

Back 51

Automatic distribution of traffic over multiple links or processors to optimize response.

Front 52

Mirroring

Back 52

Fault-tolerance technique in which one device or component duplicates the activities of another.

Front 53

Replication

Back 53

Refers to the dynamic copying of data from one location to another.

Front 54

Clustering

Back 54

Fault-tolerance technique that links multiple servers together to act as a single server - clustered servers share processing duties and appear as a single server. Clustering is more cost-effective than mirroring for large networks.

Front 55

Hardware RAID

Back 55

Includes a set of disks and a separate disk controller - managed exclusively by the RAID disk controller.

Front 56

Software RAID

Back 56

Relies on software to implement and control RAID techniques over virtually any type of hard disk - less expensive than hardware RAID. Windows 2003 server: Disk Management; NetWare Server: iManager; Red Hat Linux: Disk Druid.

Front 57

RAID Level 0

Back 57

Disk stripping - data is written in 64-KB blocks equally across all disks in the array - not fault-tolerant, but improves performance by utilizing multiple disk controllers.

Front 58

RAID Level 1

Back 58

Provides redundancy through a process called disk mirroring (data from one disk is copied to another disk automatically as the info is written - dynamic backup).

Front 59

Disk Duplexing

Back 59

Data is copied from one disk to another when it is saved, like disk mirroring - separate disk controller is used for each different disk.

Front 60

RAID Level 3

Back 60

Disk Striping with Parity ECC (Error Correction Code) - algorithm used to detect and correct errors.

Front 61

Parity Error Checking

Back 61

Process of comparing the parity of data read from disk with the type of parity used by the system.

Front 62

RAID Level 5

Back 62

Disk Striping With Distributed Parity - highly fault-tolerant, most popular data storage techique in use today. Data is written in small blocks across several disks. Parity error checking information is distributed among the disks.

Front 63

Hot Spare

Back 63

Used in RAID Level 5, a disk or partition that is part of the array, but used only in case one of the disks fails.

Front 64

Full Backup

Back 64

All data on a server is copied to storage media, regardless of whether the data is new or changed. After backing up the files, a full backup unchecks or turns off the archive bit.

Front 65

Incremental Backup

Back 65

Only data that has changed since the last full or incremental backup is copied to storage media. The archive bit is then turned off.

Front 66

Differential Backup

Back 66

Only the data that has changed since the last full backup is copied to storage media. The archive bit is NOT turned off.

Front 67

Backup rotation scheme

Back 67

Plan that specifies when and how often backups will occur.

Front 68

Grandfather-father-son backup strategy

Back 68

Daily: son; Weekly: father; Monthly: grandfather

Front 69

Disaster Recovery

Back 69

Process of restoring your critical functionality and data after an enterprise-wide outage that affects more than a single system or a limited group of users.

Front 70

Cold Site

Back 70

Place where the computers, devices and connectivity necessary to rebuild a network exist, but they are not appropriately configured, updated or connected.

Front 71

Warm Site

Back 71

Place where the computers, devices and connectivity necessary to rebuild a network exist, with some appropriately configured, updated or connected.

Front 72

Hot Site

Back 72

Place where the computers, devices, and connectivity necessary to rebuild a network exist, and all are appropriately configured, updated and connected to match your network's current site.

Front 73

Security Audit

Back 73

Thorough exam of each aspect of the network to determine how it might be compromised - performed at least anually and preferably quarterly. It rates severity of effects and likelihood.

Front 74

Social Engineering

Back 74

Manipulating social relationships to gain access to a network or workstation.

Front 75

IP Spoofing

Back 75

Obtain internal IP addresses, then use those addresses to pretend that they have authority to access your internal network from the Internet.

Front 76

Flashing

Back 76

During Internet chat, users might send commands that cause the screen to fill up with garbage character and require them to terminate their chat sesion.

Front 77

Denial-of-service Attack

Back 77

System becomes unable to function because it has been deluged with data tranmissions or otherwise disrupted.

Front 78

Roles of Security Response Policy

Back 78

Dispatcher, Manager, Technical Support Specialist, and Public Relations Specialist.

Front 79

Bio-recognition

Back 79

Device scans an individual's unique physical characteristics (color patterns of the iris, geometry of hand, etc).

Front 80

Packet-Filtering Firewall

Back 80

Router (or computer with software installed) that examines the header of every packet of data it receives to determine whether that type of packet is authorized to continue to its destination. (Also called screening firewalls). Network Layer of OSI.

Front 81

Proxy Server

Back 81

Software application on a network host that acts as an intermediary between the external and internal networks, screening all incoming and outgoing traffic. Network host = proxy server, Application Layer of OSI. Windows: ISA Server; Unix: Squid; Novell: BorderManager.

Front 82

Login Restrictions

Back 82

Time of day, total time logged on, source address, and unsuccessful logon attempts.

Front 83

Dictionary Attack

Back 83

Use of programs that try a combination of your user ID and every word in a dictionary to gain access to the network.

Front 84

Encryption

Back 84

Use of an algorithm to scramble data into a format that can be read only by reversing the alogrithm.

Front 85

Key Encryption

Back 85

Key is a random string of characters that is inserted into the data's bits serveral times in different sequences to generate a unique data block.

Front 86

Ciphertext

Back 86

Scrabled data block that is the result of inserting a encryption key into data.

Front 87

Brute Force Attack

Back 87

Trying numerous possible character combinations to find the key that will decrypt encrypted data.

Front 88

Private Key Encryption

Back 88

Data is encrypted using a single key that only the sender and the receiver know - also known as symmetric encryption because the same key is used during both the tranmission and reception of data.

Front 89

Public Key Encryption

Back 89

Data is encrypted using 2 keys: one is a key known only to a user, and other is a public key associated with the user. It uses a public key server, which is a publicly accessible host that freely provides a list of users' public keys.

Front 90

Key Pair

Back 90

Combination of a public key and a private key.

Front 91

Asymmetric Encryption

Back 91

Another name for public key encryption because it requires the use of two different keys.

Front 92

Digital Certificate

Back 92

Password protected and encrypted file that holds an individual's identification information, including a public key.

Front 93

Handshake Protocol

Back 93

Allows the client and server to authenticate each other and establishes terms for how they will securely exchange data. Uses client_hello and server_hello messages.

Front 94

DNS Spoofing

Back 94

When hacker's forge name server records to falsify the host's identity.

Front 95

OpenSSH

Back 95

Open source versions of the protocol suite SSH (Secure Shell).

Front 96

Port-Forwarding

Back 96

Redirect traffic that would normally use an insecure port to an SSH-secured port.

Front 97

Key Management

Back 97

Way in which 2 nodes agree on common parameters for the keys they'll use

Front 98

Authentication Protocols

Back 98

Rules that computers follow to accomplish authentication.

Front 99

Mutual Athentication

Back 99

Both computers verify the credentials of the other - clients authenticate the server, and vice versa.

Front 100

Kerberos

Back 100

Cross-platform authentication protocol that uses key encryption to verify the identity of clients and to securely exhange information after a client logs onto the system. Requires a client to prove its identity through a 3rd party.

Front 101

War Driving

Back 101

Driving around with a laptop configured to receive and capture wireless data tranmissions.

Front 102

802.11i

Back 102

Specifies the AES encryption method and mixes each packet in a data stream with a different key. More secure than WEP, and will probably replace in the future.

Front 103

Project Management

Back 103

Practice of managing staff, budget, timelines, and other resources and variables to achieve a specific goal within given bounds. 4 phases: initiation, specification, implementation and resolution.

Front 104

Milestone

Back 104

Reference point that marks the completion of a major task or group of tasks in the project and contributes to measuring the project's progress.

Front 105

Feasibility Study

Back 105

Outlines the costs and benefits of the project and attempts to predict whether it will result in favorable outcome - should be performed for any large-scale project before resources are committed to the project.

Front 106

Needs Assessment

Back 106

Process of clarifying the reasons and objectives underlying a proposed change. It involves interviewing users and comparing preceptions to factual data - determine the appropriate scope and nature of the proposed change.

Front 107

Sponsors

Back 107

Managers and other who oversee resource allocation - they don't necessarily participate in project tasks or supervise project teams, but they can lobby for funding, change deadlines, and negotiate on vendor contracts.

Front 108

Stakeholder

Back 108

Person who is affected by a project, like a user on a network that's being upgraded.

Front 109

Gantt Chart

Back 109

Popular method for depicting when projects begin and end along a horizontal timeline.

Front 110

Contingency Planning

Back 110

Process of identifying steps that minimize the risk of unforeseen events that could affect the quality or timeliness of the project’s goals.

Front 111

Pilot Network

Back 111

Small-scale network that stands in for the larger network – similar enough to closely mimic the larger network’s hardware, software, connectivity, unique configurations and load.

Front 112

Network Management

Back 112

Assessment, monitoring and maintenance of all aspects of a network.

Front 113

Baseline Assessment

Back 113

Includes: Physical Topology, Access Method, Protocols, Devices, Operating Systems and Applications

Front 114

Performance Management

Back 114

Monitors how well links and devices are keeping up with the demands placed on them.

Front 115

Fault management

Back 115

Detection and signaling of device, link or component failure.

Front 116

Polling

Back 116

Collection of data from multiple networked devices at regular intervals.

Front 117

Asset Management

Back 117

Identifying and tracking the hardware and software on your network (number of components on the network, each device’s configuration files, model, number, serial number, location on the network and tech. Support contact. Software information includes version number, vendor, licensing and technical support contact.

Front 118

Patches

Back 118

Correction, improvement, or enhancement to a particular piece of software application. Differs from revision or software upgrade in that it changes only part of an application, leaving most of the code untouched.

Front 119

Software Upgrade

Back 119

Major change to a software package’s existing code – designed to add functionality and fix bugs in the previous version of the client.

Front 120

Backleveling

Back 120

Process of reverting to a previous version of software after attempting to upgrade.