136 results

T1 (aka: T1 Line) Type of dedicated leased line. Composed of 24 64Kbps DS0 channels for a total bandwidth of 1.544Mbps. Originally used for telephony networks to carry one conversation in a single channel.  Wikipedia         

T3 Line    Wikipedia         

T568A g.G.o.B.b.O.br.BR   Wikipedia  Wikipedia       

T568B o.O.g.B.b.G.br.BR   Wikipedia  Wikipedia       

table (aka: relation) Collection of related data held in columns and rows within a database. Persistent representation of a logical relation in a database. Table and relation are used interchangeably because the relational model's creator, E. F. Codd, used the two terms as synonyms.   Wikipedia         

tag Helps with the frame election process.            

tail Command that displays the end of a file. (head shows the beginning.) For example tail -f /var/log/messages can be used with the -follow switch to see syslog messages and print new data as the file grows.   Wikipedia  YouTube  Linux 101 Hacks     

tailored web design (aka: Responsive Web Design (RWD))   Wikipedia         

tar (tape archive) Both a file format and a program. Example:

tar -zxvf
 Introduced with version 7 UNIX in 1979.  Wikipedia         

Taylor Otwell Developer of Laraval.            

TC Shell (tcsh) Default shell in FreeBSD. Previosly used as the default shell before Mac OS X 10.3.  Website  Wikipedia       

TCP ACK scan -sA Nmap scan option that typically used to get past a firewall.   Nmap         

TCP Flag SYN, ACK, FIN, SYN/ACK            

TCP Segment Source Port, Destination Port, Sequence Number, Acknowledgement Number, Header length, Reserved, Control bits, Window, Checksum. Urgent, Options, Application Layer Data.   Wikipedia         

TCP SYN scan -sS Default and most popular Nmap scan option. Used to perform a TCP SYN stealth port scan.   Nmap         


tebibyte (TiB) (1024 gibibytes = 1,099,511,627,776 bytes) Defined by the International Electrotechnical Commission (IEC)   Wikipedia         

technical controls e.g. user authentication (login) and logical access controls, antivirus software, firewalls.   Wikipedia         

tee Outputs to a file and writes to standard output.   Wikipedia         

Telecommunications Industry Association (TIA)    Wikipedia         

Telelocator Alphanumeric Protocol (TAP)    Wikipedia         

Telenet Commercial packet switched network. Went into service in 1974.  Wikipedia         

Telnet Protocol used to provide remote CLI access devices such as servers and networking equipment. Does not encrypt transmission.   Wikipedia         

Temporal Key Integrity Protocol (TKIP) Security protocol used in IEEE 802.11 as a temporary solution to WEP. Published October 31, 2002. Deprecated in 2012.  Wikipedia         

temporary files usually located in the following folders: C:\Windows\Temp C:\Users\User_Name\AppData\Local\Temp %USERPROFILE%\AppData\Local\Temp            

terabyte (TB) 1 trillion bytes.   Wikipedia         

Terminal Access Controller Access-Control System (TACACS (TCP or UDP port 49) Family of related protocols handling remote authentication and related services for networked access control through a centralized server. Originally developed by BBN Technologies for administering MILNET in 1984.  Wikipedia         

Terminal Access Controller Access-Control System Plus (TACACS+) Protocol developed by Cisco. Although derived from TACACS, TACACS+ is a separate protocol that handles authentication, authorization, and accounting (AAA) services. Encrypts an entire authentication packet, rather than just the password. Released as an open standard beginning in 1993.  Wikipedia         

terminal length Used in conjunction with another command to specify number of lines displayed in terminal.            

Tesla Motors American automotive and energy company. Founded July, 2003.    Wikipedia       

test Builtin utility for Bash. Brackets [ ] can be put around what is being tested instead.            

Test Anything Protocol (TAP)    Wikipedia         

TEST-NET Addresses Reserved for teaching and learning purposes   Wikipedia         

Test-Path PowerShell cmdlet.            

tethering Using a smartphone or tablet as a personal hotspot.            

Text Reckoning And Compiling (TRAC) Programming language. Developed in the early 1960s by Calvin Mooers.  Wikipedia         

TFTP server Stores information that can be retrieved easily. Often used for device recovery.            

The Dark Knight Second film in the Christopher Nolan's The Dark Knight Trilogy. Released July 18, 2008.  IMDB  Wikipedia       

The Jazz Singer  first feature-length motion picture with synchronized sound October 6, 1927.  Wikipedia         

The Matrix  Released March 31, 1999.  IMDB  Wikipedia       

The Vintage Computer Festival (VCF) Founded by Sellam Ismail in 1997.   Wikipedia         

This isn't Pico (TIP) Original name for the text editor nano.   Wikipedia         

Thomas Jefferson  Invented an encryption system believed to have been used between 1790-1793.           

thread Smallest sequence of programmed instructions that can be managed independently by a scheduler.   Wikipedia         

threat Event that exploits a vulnerability’s potential to do harm to an asset. Can be adversarial (i.e. hacking; individual cracker or a criminal organization), accidental (i.e. misconfiguration), structural (i.e. a computer malfunctioning), or environmental (i.e. natural disaster such as an earthquake, a fire, or a tornado).   Wikipedia         

threat agent (aka: threat actor) Person or entity that initiates a threat.   Wikipedia         

threat assessment Often done alongside a risk assessment.


three-tier hierarchical design Handles resources efficiently and scales easily.            

three-way handshake used by TCP   Wikipedia         

Threefish Symmetric-key tweakable block cipher.   Wikipedia         

Threshold Codename for Windows 10.   Wikipedia         

Threshold 2 (TH2) (aka: Cumulative Update for Windows 10 Version 1511 for x64-based Systems, November Update, (KB3118754), or Build version 10.0.10586.) First major update to Windows 10. Released November 12, 2015  Wikipedia         

through-hole Leads are inserted into holes in the PCB.   Wikipedia         

throughput The maximum amount of data that can be downloaded or uploaded at a time.   Wikipedia         

Thunderbolt Developed by Intel and used mainly by Apple. Allows for seed up to 10x faster than USB 3.0   Wikipedia         

Ticket Granting Service (TGS) Part of Kerberos that generates a session key.            

Ticket Granting Ticket (TGT) (aka: Security Identifier (SID)) Part of Kerberos that is provided by the Authentication Service.            

Tier 1 ISP Directly connected to the internet backbone. Primarily serves very large companies and Tier 2 ISPs            

Tier 2 ISP Primarily serves large companies and Tier 3 ISPs.            

Tier 3 ISP Primarily serves small/medium sized companies and homes.            

Tiger (Mac OS X 10.4)   Wikipedia         

tilde ~ HOME directory in Bash.            

Tim Berners-Lee Inventor of the World Wide Web. Born June 8, 1955.  Wikipedia         

time Used to determine the duration of execution for a particular command.   Wikipedia         

time Command that displays or sets the system time. Use date for UNIX-based systems or clock set/show clock for IOS.   Wikipedia         

Time Division Multiple Access (TDMA)    Wikipedia         

Time Division Multiplexing (TDM) Splits the bandwidth of a single link into multiple time slots with a MUX.   Wikipedia         

Time Warner Cable (TWC) Second largest cable company next to Comcast.   Wikipedia         

Time-to-Live (TTL) 8-bit binary value used to limit the lifetime of a packet.   Wikipedia         

times & times; HTML symbol for the multiplication sign.            

tip and ring Red and green wires found in an RJ-11 wall jack, which carry voice, ringing voltage, and signaling information between an analog device (for example, a phone or a modem) and a telephone's wall jack.            

title Command that sets the window title for a CMD.EXE session.            

TLD4 malware            

token Sequence of nonblank characters on the command line. Basicaly a word.            

toll network Equipment inside the WAN provider network. (Long-haul, all-digital, fiber, switches, routers,...)            

toner probe Used to trace the location of a cable. Can find a cable when a tone generator is atached to one end.   Wikipedia  Netacad       

Top Level Domain (TLD) (.com .org .au .co .jp...)   Wikipedia         

tracing Logging information about a program to later be used for debugging.   Wikipedia         

TCP connect scan -sU Nmap scanning mothod. Similar to the TCP SYN scan, except that it does complete the three-way handshake.   Nmap         

The Internet Health Report Open source documnet from Mozilla explaining the health of the internet with data from multiple sources. Announced January 19, 2017.  Website  Mizilla Blog       

This Day in Tech History The history of technoligy in a daily blog.   Website         

Titan Supercomputer from Cray. Operational October 29, 2012.  Wikipedia         

Titanfall  Released March 11, 2014.  Wikipedia         

Titanfall 2  Released October 28, 2016.  Wikipedia         

tone generator Sends a tone through the length of a cable.   Wikipedia  Netacad       

topology Layout of a network that describes where devices will go and how they will be connected. There are two kinds of topologies, logical and physical.   Wikipedia         

Total Cost of Ownership (TCO)    Wikipedia         

TouchWiz Developed by Samsung.   Wikipedia         

TO_NUMBER Oracle function used to convert a character string into a number. Digits are represented by “9”.            

traceroute Network Command-line utility that displays the path (route) and measures the delay of packets. Traces packets to a destination address for troubleshoot issues. UNIX-like systems use traceroute, while Windows-based systems use the shorter tracert.   Wikipedia         

tracert Windows version of the traceroute command. Use traceroute for UNIX based systems.   Wikipedia         

track One complete circle on one side of a hard drive's platter where data is written and read. A track is broken into multiple sectors.     Netacad       

traffic classification Categorizes packets automatically based on parameters such as port or protocol.   Wikipedia         

transceiver Both a transmitter and a receiver. Similar to a repeater.   Wikipedia         

transformer    YouTube (Make:)         

transformer Among the most common electrical devices. Can change the values of voltage, current and impedance but cannot change the frequency.


transistor    Wikipedia  YouTube (Make:)       

translate (tr) Replace or remove specific characters in its input data set.   Man Page  Wikipedia       

translation NAT64 allows IPv6 to communicate with IPv4            

Transport Control Protocol (TCP) (Layer 4 protocol.) Breaks data into segments for IP before they are sent. Full-duplex. Connection oriented. Has flow-control for each byte stream. TCP segments are marked with flags. Robert Kahn and Vitron Cerf began work on TCP in 1973.   Wikipedia  Wikipedia (List of Ports)       

Transport Control Protocol/Internet Protocol (TCP/IP) (aka: TCP/IP model, Department of Defense (DoD) model) Protocol suite. The IP suite is commonly known as TCP/IP because the foundational protocols in the suite are the Transmission Control Protocol (TCP) and the Internet Protocol (IP).

1 network interface
2 internet
3 transport
4 application

 Predates the OSI model, a more comprehensive reference framework for general networking systems. Replaced proprietary protocol suits such as AppleTalk and Novell's Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX).  Wikipedia         

Transport Layer (OSI Layer 4) Provides transport transfer of data between hosts. Responsible for services such as connection-oriented communication, reliability, flow control, and multiplexing. Layer 4 destination port is used to identify the upper layer protocol.   Wikipedia         

Transport Layer (OSI Layer 4) Conceptual layer in the internet protocol suite (TCP/IP) and the OSI model. Divides long communications into smaller data packages and handles error recognition and correction.   Wikipedia         

Transport Layer Security (TLS) Successor to SSL. TLS 1.0 first defined in RFC 2246 January 1999.  Wikipedia  RFC 2246       

Transport Layer Security 1.1 (TLS 1.1)  Defined in RFC 4346 April 2006.  Website  Wikipedia       

Transport Layer Security 1.2 (TLS 1.2)  Defined in RFC 5246 August 2008.  Website  Wikipedia       

Transport Layer Security 1.3 (TLS 1.3)  Working draft as of July 2016.    Wikipedia       

Transport Mode Firewall mode on the Cisco ASA. Functions as a Layer 2 device. Protects only the packets payload. Works well with GRE.   Netacad         

transposition Characters are rearranged. Used in part by DES and 3DES.            

trap messages Solution to the main disadvantage of SNMP polling. Generated by SNMP agents and sent to the NMS to inform it of events without waiting for it to be polled.   Wikipedia         

tree Command to graphically display the directory structure of a drive or path.   Wikipedia         

TrendMicro Security software company based in Tokyo, Japan. Founded in 1988.  Wikipedia  Website       

Triple Data Encryption Standard (3DES) (Legacy) Applying DES three times in a row to a plaintext block. Can be used by IPsec to encrypt data. Three 56-bit encryption keys per 64-bit block. Symmetric.   Wikipedia         

Trivial File Transfer Protocol (TFTP) Used for connectionless active file transfer. Uses port 69.   Wikipedia         

Trojan horse Software that appears to be useful but is actually malicious.

remote access
data sending
security software disabler
   Wikipedia  YouTube (TheCuriousEngineer)  Netacad     

trunk Single connection between two points such as a switch or branch office.   Wikipedia         

Trusted Execution Environment (TEE) Isolated environment running alongside a mobile OS.   Wikipedia         

Trusted Platform Module (TPM) (aka: ISO/IEC 11889) Dedicated microcontroller that performs cryptographic functions, such as encrypting an entire hard drive.   Wikipedia         

trustee    Website  Wikipedia       

TrustSec Cisco borderless service. Secures the network based on polices in addition IP/MAC addresses. Different departments can determine who gets access to what while all being spelled out in plain English.   YouTube (Cisco - Fundamentals of TrustSec)  Cisco  YouTube (Cisco - TrustSec Takes the Complexity Out of Network Security)     

TUN/TAP Virtual network kernel devices.   Wikipedia         

Tunnel Mode (aka: IP-in-IP encryption) Secures the entire IP packet.    Netacad         

tunneling Transporting an IPv6 packet over an IPv4 network. IPv6 packet is encapsulated inside an IPv4 packet. (for networks that don't support dual stack)   Wikipedia         

Turing test A test of a machine's ability to exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human.            

Twentieth Anniversary Macintosh  Released March 20, 1997.  Wikipedia         

Twitter  Founded March 21, 2006.  Wikipedia         

Two-Factor Authentication (2FA) (aka: two-step verification)   Wikipedia         

two-tier hierarchical design Core and distribution layers implemented into a single layer.            

Twofish Symmetric key block cipher. One of the five finalists of the AES contest, but was not standardized  Wikipedia         

Twttr Group SMS social network launched by Odeo. Released July 15, 2006.    TechCrunch       

type Shell builtin. Command that describes how its arguments would be interpreted if used as command names. Added to the Bourne Shell in 1984.  Wikipedia (UNIX)         

TYPE Command that displays the contents of a text file.   Wikipedia (DOS)         

Type Length Value (TLV) The data portion of an EIGRP message that is encapsulated in a packet.   Wikipedia         

Type of Service (ToS) Part of an IPv4 packet header now represented by Differentiated Services Code Point (DSCP).   Wikipedia (ToS)  Wikipedia (IPv4 Header)       

type system    Wikipedia