Network+ 2005 Acronyms & Abbreviations (Part Iii)

Front 1

CIDR

Back 1

Classless Inter-Domain Routing (classless routing or supernetting) - provides additional ways of arranging network and host information in an IP address. Conventional network class distinctions don't exist. CIDR moves bits to the left instead of the right like in classful addressing.

Front 2

NAT

Back 2

Network Address Translation - technique in which IP addresses used on a private
network are assigned a public IP address by a gateway when accessing a public network.

Front 3

ICS

Back 3

Internet Connection Sharing - configured to translate requests to and from the Internet on behalf of other computers on the network. The ICS Host acts as a DHCP server, DNS resolver and NAT gateway for clients on its LAN.

Front 4

SMTP

Back 4

Simple Mail Transfer Protocol - responsible for moving messages from one mail server to another over TCP/IP-based networks. SMTP belongs in the Application layer (OSI) and relies on TCP at the Transport layer. Port 25

Front 5

MIME

Back 5

Multipurpose Internet Mail Extensions - standard for encoding and interpreting binary files, images, video, and non-ACSII character sets within an email message. MIME doesn't replace SMTP, but works in conjuction with it.

Front 6

POP3

Back 6

Post Office Protocol 3 - Application layer protocol used to retrieve messages from a mail server. Port 110

Front 7

IMAP

Back 7

Internet Message Access Protocol - mail retrievel protocol that was developed as a more sophisticated alternative to POP3. IMAP can replace POP3 without changing email programs. Biggest advantage is that users can store messages on the mail server, rather than always downloading them to the local machine.

Front 8

VoIP

Back 8

Voice over IP - use of packet-switched networks and the TCP/IP protocol to transmit voice conversations. It lowers the cost for calls, supplies new or enhanced features, and centralizes voice and data network management.

Front 9

IP-PBX

Back 9

IP-Private Branch Exchange - telephone switch used to connect call within a private organization.

Front 10

TDR

Back 10

Time Domain Reflectometer - issues a signal on a cable and then measures the way the signal bounces back.

Front 11

OTDR

Back 11

Optical Time Domain Reflectometer - same as a TDR, except it tranmits light-based signals of different wavelengths over fiber-optic cables.

Front 12

RAID

Back 12

Redundant Array of Independent Disks - collection of disks that provide fault-tolerance for share data and applications - group of disks is called a disk array. RAID increases storage capacity and potentially better performance.

Front 13

NAS

Back 13

Network Attached Storage - specialized storage device or group of storage devices that provide centralized fault-tolerant data storage for a network. Differs from RAID in that it maintains its own interface to the LAN. Compare NAS.

Front 14

SANs

Back 14

Storage Area Networks - distinct networks of storage devices that communicate directly with each other and with other networks. Extremely fault-tolerant and fast - uses Fibre Channel, which connects devices within SAN and also connects the SAN to other networks (2Gbps throughput).

Front 15

DES ("dez")

Back 15

Data Encryption Standard - popular, private (symmetric) encryption which uses a 56-bit key.

Front 16

3DES

Back 16

Triple Data Encryption Standard - modern implemenation of DES, 3DES provides greater security by weaving a 56-bit key through data 3 times, using 2 or 3 different keys.

Front 17

AES

Back 17

Advanced Encryption Standard - weaves keys of 128, 160, 192 or 256 bits through data multiple times - alogrithm is known as "Rijndael".

Front 18

RSA

Back 18

Popular public key algorithm in use today. Developed by 3 men with with last name initials RSA. RSA is used to secure e-commerce transactions.

Front 19

RC4

Back 19

Used in conjuction with RSA, RC4 weaves a key with data multiple times, as a computer issues the stream of data.

Front 20

PGP

Back 20

Pretty Good Privacy - public key encryption system that can verify the authencity of an email sender and encrypt email data in tranmissions.

Front 21

SSL

Back 21

Secure Sockets Layer - method of encrypting TCP/IP transmissions - including web pages and data entered into web forms - en route between the client and server using public key encryption technology.

Front 22

HTTPS

Back 22

HTTP Over SSL - uses TCP port number 443, instead of 80.

Front 23

SSL Session

Back 23

Association between client and server that is defined by an agreement on a specific set of encryption techniques.

Front 24

TLS

Back 24

Transport Layer Security - IETF standardization of SSL.

Front 25

SSH

Back 25

Secure Shell - collection of protocols that provides security for establishing a connection and security for tranmitting data - more secure than Telnet.

Front 26

SCP

Back 26

Secure Copy - allows you to copy files from one host to another securely - replaces FTP.

Front 27

SFTP

Back 27

Secure File Transfer Protocol - establishes a connection with a host and then allows a remote user to browse directories, list and copy files. More features than SCP.

Front 28

IPSec

Back 28

Internet Protocol Security - protocol that defines encryption, authentication, and key management for TCP/IP transmissions. IPSec encrypts data by adding security information to the header of all IP packets. Operates at Network layer of OSI.

Front 29

RADIUS (and TACACS)

Back 29

Remote Authentication Dial-In Service - service used to authenticate users in environments in which many simultaneous dial-up connections must be supported and their user IDs and passwords managed. TACACS is earlier version of RADIUS.

Front 30

PAP

Back 30

Password Authentication Protocol - used in PPP, it sends an authentication request that includes its credentials (user name and password). Not very secure.

Front 31

CHAP (and MS-CHAP, MS-CHAPv2)

Back 31

Challenge Handshake Authentication Protocol - operates over PPP, but encrypts user names and passwords for transmission. Requires 3 steps to complete authentication process, which is called a three-way handshake.

Front 32

EAP

Back 32

Extensible Authentication Protocol - extension to the PPP protocol suite, it is only a mechanism for authenticating clients and servers, it doesn't perform authentication on its own. Supported by all modern OSs.

Front 33

WEP

Back 33

Wireless Equivalent Privacy - uses keys both to authenticate network clients and to encrypt data in transit. When configuring WEP, you establish a character string required to associate with the AP, or network key.

Front 34

WPA

Back 34

Wi-Fi Protected Access - subset of 802.11i, WPA specifies RC4 encryption rather than AES. An updated version is called WPA2.

Front 35

MIB

Back 35

Management Information Base

Front 36

SNMP

Back 36

Simple Network Management Protocol: part of TCP/IP suite; typically runs over UDP on port 161.

Front 37

MRTG

Back 37

Multi-Router Traffic Grapher – command-line utility that uses SNMP to poll devices, collects data in a log file, then generates HTML-based views of the data.