e
e-grave (è) Wikipedia
E1 Type of dedicated leased line. Contains 32 64Kbps DS0 channels for a total bandwidth of 2.048Mbps. Wikipedia
E3 Electronic Entertainment Expo. First held May 11, 1995 - May 13, 1995 at the Los Angeles Convention Center. Website Wikipedia
E3 Type of dedicated leased line. Contains 16 DS1 channels for a total bandwidth of 34.4Mbps. Wikipedia
E3 2016 June 14, 2016 - June 16, 2016. Website Wikipedia
E3 2017 June 13, 2017 - June 15, 2017. Website Wikipedia
E3 2018 June 12-14 in Las Angeles. Website Wikipedia
E3 2019 June 11-13 in Las Angeles. Website Wikipedia
EAP Flexible Authentication via Secure Tunneling (EAP-FAST) Designed to address the weaknesses of LEAP while preserving the "lightweight" implementation. Defined in RFC 4851 May 2007. Wikipedia RFC 4851
EAP Transport Layer Security (EAP-TLS) Can handle an entire TLS. Needs server and client certificates. Wikipedia
EAP Tunneled Transport Layer Security (EAP-TTLS) Uses the TLS exchange method. Only requires server certificates. Wikipedia
EAP-MD5 Takes passwords and hashes them into a MD5 hash. Basically MSCHAP. Wikipedia
echo A command that prints to the display whatever it is told to say or turns command echoing on or off.
echo $0 | Linux command that will return the name of shell you are working in or the currently running program. |
Edge Web Browser made by Microsoft. Successor to Internet Explorer. Code named Project Spartan. Name fist announced April 29th 2015 at Build. Wikipedia
edge router Router on the parameter of a network. Three areas to secure: physical security, router hardening, operating system security.
Edvard K Sells water blocks, radiators, and other PC cooling solutions. Website
effective pixels Wikipedia
EIGRP composite metric
| K1 | (bandwidth) | 1 |
| K2 | (load) | 0 |
| K3 | (delay) | 1 |
| K4 | (reliability) | 0 |
| K5 | (reliability) | 0 |
EIGRP Convergence neighbors>topology>routing table Wikipedia
EIGRP external route Default administrative distance of 170. Shown in a routing table with EX. Wikipedia
EIGRP internal route default administrative distance of 90 Wikipedia
EIGRP IPv4 Messages Have a destination address of 224.0.0.10 and a source address of the outbound interface. Wikipedia
EIGRP IPv6 Messages Have a destination all-EIGRP-routes link-local multicast address of FF02::A and the IPv6 link-local address of the exit interface as the source. Wikipedia
EIGRP Metric The lowest bandwidth of all the outgoing interfaces between source and destination. Both EIGRP for IPv4 and IPv6 use bandwidth and delay for their composite metric. Reliability and load can also be used to calculate the metric but are not recommended. Wikipedia
EIGRP neighbor table Where router adjacencies are stored. Wikipedia
EIGRP packets
| Acknowledgement | Used to acknowledge the receipt of any EIGRP packet. Unreliable and unicast. |
| Hello | Used to discover other EIGRP routers in the network. Unreliable delivery and multicast. |
| Query | Used to request specific information from a neighbor router. Reliable delivery and multicast or unicast. |
| Reply | Used to reply to a query. Reliable and unicast. |
| Update | Convey routing information to known destinations. Reliable and multicast or unicast. |
EIGRP successor route Stored in the routing table and the topology table. Wikipedia
EIGRP summary route default administrative distance of 5 Wikipedia
EIGRP topology table Where all learned routes are stored. Wikipedia
EIGRP Update packet Convey routing information to known destinations. Reliable and Multicast or unicast. Wikipedia
El Capitan (OS X 10.11) Wikipedia
Electrolysis Mozilla Wiki
electromotive force (EMF) (Voltage or Potential difference)
Electronic CodeBook (ECB) (legacy) The simplest of the encryption modes. Message is divided into blocks, and each block is encrypted separately. Always has the same output. Used as a block cipher in DES. Wikipedia
Electronic Frontier Foundation (EFF) International non-profit digital rights group based in San Francisco, California. Founded by Mitch Kapor, John Perry Barlow, and John Gilmore July 6, 1990. Wikipedia Website
Electronic Funds Transfer (EFT)
Electronic Industries Alliance (EIA) Has standards for 19 inch racks, electrical wiring, and connectors. Wikipedia
electrophotographic (EP) print process
| 1. Processing | Printer receives and processes the image and stores a page in memory. |
| 2. Charging | Places a uniform -600V DC charge on the photosensitive drum by mean of a charging corona. |
| 3. Exposing | Laser "paints" an image onto the photosensitive drum, discharging image areas to a much lower voltage of -100V DC. |
| 4. Developing | Developing roller has charged toner stuck to it at -600V DC. As it rolls the toner toward the photosensitive drum, the toner is attracted and sticks to the areas of the drum the laser has discharged. |
| 5. Transferring | Image is transferred from the drum to the paper at its line of contact by means of the transfer corona wire (or corona roller) with a +600V DC charge. The static-eliminator strip removes the high, positive charge from the paper and the image is held to the paper. |
| 6. Fusing | Paper enter the fuser, where a fuser roller and the pressure roller make the image permanent. The paper exits the printer. |
| 7. Cleaning | Rubber scraper cleans the photosensitive drum and the fluorescent lamp discharges any remaining charge. The printer is now ready to print the next page. |
elements of risk Threat actors initiate threats, which in turn exploit vulnerabilities.
Elk Cloner Virus that spread through floppy disks for the Apple II. Made by Rich Skrenta. Wikipedia Wikipedia
Elliptic Curve Digital Signature Algorithm (ECDSA)
Elliptic-Curve Cryptography (ECC) Public key cryptography protocol used for encryption as well as digital signatures and key exchange. Reduces the time needed to generate keys. Often used on small mobile devices, due to its low power and computing requirements. Wikipedia
Emacs Comically known as "Eight Megabytes and Constantly Swapping" or "Esc-Meta-Alt-Ctrl-s" Wikipedia
Email Security Appliance (ESA)
embedded MMC (eMMC) Wikipedia
embedded system Computer system with a dedicated function inside a larger system. Wikipedia
empty set {} or Ø No solution. If an equation has no solution than the equation in called an "inconsistant equation".
enable Command that enters privilege EXEC mode on a network device.
Enable-WindowsOptionalFeature PowerShell command to enable features in Windows. Example:
Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V | Enable Hyper-V |
Encapsulating Security Payload (ESP) Provides data authentication and data encryption.
encapsulation When the network layer adds IP header information such as the IP address of the source (sending) and destination (receiving) hosts. After header information is added to the PDU, the PDU is called a packet. Wikipedia
Encapsulation Security Protocol (ESP) Provides data authentication and data encryption in tunnel mode (adds a new IP header to the original encrypted header). Does not provide integrity and authentication for the entire IP packet in transport mode (keeps the original IP address). Wikipedia
Encrypting File System (EFS) Filesystem-level encryption used to incrypt individual files and folders. This does not encrypt the entire device like BitLocker. Wikipedia
encryption Scrambling data so it can't be read unless it is unencrypted. Cisco
ENDLOCAL Command Prompt command that ends localization of environment changes in a batch file.
Endpoint security Each device manages its own security. Wikipedia Texport Technologies
EnergyWise Cisco borderless service. Helps manage energy usage of connected devices. YouTube Cisco
Enhanced Data rates for GSM Evolution (EDGE) Wikipedia
Enhanced High-speed WAN interface card (EHWIC) Cisco
Enhanced High-speed WAN interface card slot (EHWIC slot) Cisco
ESP header Same header as HMAC but encrypted with DES, 3DES, or AES. [ AES { Authentication Header | TCP header | data | IP address }] Wikipedia
EventID.Net Website
Electrically Erasable Programmable Read-Only Memory (EEPROM) Type of non-volatile memory. Flash memory is a type of EEPROM designed for high speed and high density. Wikipedia
Electronic Numerical Integrator And Computer (ENIAC) First electronic general-purpose computer. Announced February 14, 1946. Wikipedia
Electrostatic discharge (ESD) When built up static electricity transfers form one object to another. Can damage computers and other electronics. Increased likelihood in low humidity. Wikipedia Netacad
Elementary OS Linux distribution based on Ubuntu. First released March 31, 2011. Website Wikipedia
Enhanced Interior Gateway Routing Protocol (EIGRP) Internal gateway, distance vector, classless protocol. Creates and maintains the topology table, neighbor table, and the best path(s) in the routing table. Has an administrative distance of 90 and uses multicast address 224.0.0.10. Protocol number of 88. Uses DUAL. Establishes neighbor adjacencies with hello packets. Can be configured with authentication at the router. Sends out only partial and bounded updates. (Only sends route changes to the routers it affects.) Was originally Cisco proprietary but Cisco released basic functionality to the IETF and it is now an 'open' standard. Introduced in 1993. Wikipedia Cisco RFC 7868
Enhanced Interior Gateway Routing Protocol for IPv6 (EIGRP for IPv6) EIGRP on IPv6 uses multicast address FF02::A. Uses the all-EIGRP-routers link-local multicast address as the destination address for EIGRP messages. The source and destination addresses are the only difference between EIGRP and EIGRP for IPv6. Made available in Cisco IOS, Release 12.4(6)T.
Enigma machine Invented by Arthur Scherbius in 1918. Wikipedia
enterprise network A large business environment with many users, locations, and systems. Must have support for critical applications, converged network traffic, diverse business needs, and provide centralized administrative control. Netacad
entity integrity Concerned with ensuring that each row of a table has a unique and non-null primary key value; this is the same as saying that each row in a table represents a single instance of the entity type modelled by the table. A requirement of E. F. Codd in his seminal paper is that a primary key of an entity, or any part of it, can never take a null value. Wikipedia
entrance facility Wikipedia
enumeration Ordered listing of all the items in a set. Wikipedia
environment variable (aka: keyword variable) Variables such as PATH or HOME in Bash that have special meaning to the shell. %USERPROFILE% is an example environment variable in Windows that specifies the path to the current user account. In Windows, environment variables can be managed in; Control Panel > System > Advanced system settings > Advanced tab > Environment Variables Wikipedia Netacad
equal (eq) Comparison operator. =, ==, -eq
equal cost load balancing Two or more paths to a destination with the same metric cost.
equation standard form of a line: Ax + By = C Wolfram|Alpha
Erasable Programmable Read Only Memory (EPROM) Type of non-volatile memory. Wikipedia
erase Command that deletes one or more files.
Ernst Heinrich Weber German physician who is considered one of the founders of experimental psychology. (June 24, 1795 - January 26, 1878) Wikipedia
Error-Correcting Code (ECC) Wikipedia
Error-Correcting Code (ECC) memory Wikipedia
Essential Phone (officially (aka: Phone, PH-1) Announced May 30, 2017. Releasead August 25, 2017. Website Wikipedia
EtherChannel Combines multiple physical connections into one logical or "virtual" connection. When EtherChannel is set up, the virtual interface is known as a port channel and physical interfaces are a port channel interface. EtherChannel can be configured using PAgP or LACP or even as a static unconditional. Wikipedia
Ethernet Frame Adds headers and trailers to a Layer 3 PDU. Each section of a frame is called a field. Has no TTL. Two kinds of Ethernet Frames are IEEE 802.3 and Ethernet II. Wikipedia
Ethernet II Based on the DIX Ethernet standard.
[ Preamble (8 bits) | Destination Address (6 bits) | Source Address (6 bits) | Type (2 bits) | Data (PDU, 46-1500 bits) | Frame Check Sequence (4 bits) ]
Ethernet private line (EPL) Wikipedia
Ethernet virtual private line (EVPL) Wikipedia
EtherType (0x0800) Two-octet field in an Ethernet frame. Wikipedia
EVGA GeForce GTX 1080 Ti SC Black Edition GAMING Released April 24, 2017. Newegg
EVGA GeForce GTX 1080 Ti SC2 GAMING Released April 24, 2017. Newegg
evil twin A fraudulent wireless access point that appears to be legitimate, set up to eavesdrop on wireless communications. Wireless LAN equivalent of the phishing scam. Wikipedia
Evolved High-Speed Packet Access (HSPA+) Wireless broadband service similar to WiMAX. Maximum data rate is 84Mbps.
EX An external EIGRP route. AD is 170. Wikipedia
exabyte (EB) 1000 petabytes Wikipedia
Excel Spreadsheet application from Mricosoft. Fisrt released September 30, 1985. Website Wikipedia Microsoft (Shortcuts)
Exchange Mail server from Microsoft. First released April 11, 1993. Website Wikipedia
Exchange Admin Center (EAC) TechNet
Exchange Management Console (EMC)
exclamation mark ! (aka: bang)
| Decimal | Hexadecimal | Binary |
| 32 | 21 | 00100001 |
eXclusive OR (XOR) Logical operation that generates a binary 1 (true) when two inputs differ. When two inputs are the same, this generates a binary 0 (false). Used by Electronic Codebook (ECB) and Cipher Block Chaining (CBC). Wikipedia
exit Quits the CMD.EXE program (command interpreter).
Experimental Addresses 240.0.0.0 to 255.255.255.254 are listed as reserved for future use. Could technically be used at a latter date but for now are just for testing. RFC 3330
Explicit Congestion Notification (ECN) Part of an IPv4 header. Wikipedia Wikipedia (IPv4 Header)
ExpressCard (initially called NEWCARD) Developed by the PCMCIA as a way to support USB 2.0, USB 3.0, and PCI Express in laptops. two form factors, ExpressCard/34 (34 mm (1.3 in) wide) and ExpressCard/54 (54 mm (2.1 in) wide). First released in 2003. Wikipedia
ExpressCard 1.x Supports USB 2.0 at 480Mbps and PCIe 1.0 x1 at 2.5Gbps. Wikipedia
ExpressCard 2.0 Supports PCIe 2.0 x1 or USB 3.0 at 5Gbps. Standardized March 4, 2009. Wikipedia
Expression Values. Typically use function call notation in programming. Wikipedia
extended ACL permit or deny traffic based on Layer 3 and Layer 4 (protocol type, source and destination ip, and source and destination TCP or UDP ports). Should be placed close to the source. Extended numbered ACLs can use numbers 100-199 and 2000-2699 (798 total).
Extended Backus Wikipedia
Extended Binary-Coded Decimal Interchange Code (EBCDIC) Character encoding developed by IBM. Wikipedia
Extended Data Out DRAM (EDO DRAM)
Extended File Allocation Table (exFAT) Microsoft proprietary file system for flash drives. Wikipedia
eXtended Frequency Range (XFR) Allows AMD CPUs to achieve higher clock frequencies with better cooling.
Extended Industry Standard Architecture (EISA) Wikipedia
extended ping Where a source interface or address is specified.
Extended Service Area (ESA) Where ESSs can communicate. Wikipedia
Extended Service Set (ESS) The combination of 2 or more APs (BSSs) through a common wired DS. Identified with an SSID. Wikipedia
Extended TACACS (XTACACS) Proprietary extension to TACACS. Both TACACS and XTACACS allow a remote access server to communicate with an authentication server to determine if the user has access to the network. Introduced by Cisco Systems without backwards compatibility to the original protocol in 1990. Wikipedia
Extended Unique Identifier (EUI)
Extensible Application Markup Language (XAML) Developed June 2008 by Microsoft. Wikipedia
Extensible Authentication Protocol (EAP) Authentication framework created as a better authentication method to PPP. Proposed as a standard in RFC 2284, March 1998. Wikipedia RFC 3748 RFC 5247 RFC 7057 RFC 2284
Extensible HyperText Markup Language (XHTML) Wikipedia W3Schools
Extensible Markup Language (XML) Wikipedia
Extensible Messaging and Presence Protocol (XMPP) Wikipedia
Extensible Storage Engine (ESE) The directory service component that runs as Esent.dll. ESE manages the tables of records that comprise the directory database. TechNet
Exterior Gateway Protocol (EGP) Used for routing outside an Autonomous System. BGP is the only current EGP and is used by the internet. BGP is often used in place of the name EGP. Wikipedia
Extreme Programming (XP) Wikipedia