l
L Local route in a routing table.
L2TP/IPsec (UDP port 1701) Layer Two Tunneling Protocol (L2TP) running through an IPsec tunnel for security. Standardized in IETF RFC 3193 November 2001. Wikipedia RFC 3193
label DOS command that creates, changes, or deletes the volume label of a disk.
Label Switch Router (LSR) MPLS element that makes frame-forwardig decisions based on lables applied to frames.
Lam Research Website
Land Grid Array (LGA) Pins are on the socket instead of the integrated circuit. Wikipedia
Landset 7 Satellite used for global satellite images. Launched on April 15, 1999. Wikipedia
Laravel PHP web framework developed by Taylor Otwell. First released as a beta June 9, 2011. Website Wikipedia
Laravel 5.3.0 Released August 23, 2016. Website Wikipedia
Laravel 5.4.0 Released January 24, 2017. Website Wikipedia
Laravel 5.5.0 Released August 30, 2017. Laravel News Wikipedia
Laravel 5.6.0 Released February 7, 2018. Laravel News Wikipedia
Large Link-State Database (LSDB)
Larry Wall Developer of Perl. Wikipedia
laser printer Should output these voltages when tested with a multimeter.
| Pin 1 | +5v |
| Pin 5 | -5v |
| Pin 9 | +24v |
LaserDisc (LD) Type of optical disc with a 0.3 GB capacity. Released December 15, 1978. Wikipedia
last mile Wikipedia
Latin America and Caribbean Network Information Centre (LACNIC) Regional Latin-American and Caribbean IP address registry. Wikipedia LACNIC
Latitude Business laptop from Dell. Wikipedia
Latitude E6410 Laptop from Dell. Website Wikipedia
Latitude E6430 Laptop from Dell. Website Wikipedia
Latitude E6530 Laptop from Dell. Website Support Wikipedia
Lawrence Livermore National Laboratory (LLNL) Home to the IBM Sequoia. Established 1952. Website Wikipedia
Layer 1 (physical layer) Transmits Bits across local media. Wikipedia
Layer 2 (data Link layer.) Packages Layer 3 PDUs into frames. Manages access to frames and network media. Wikipedia
Layer 2 address (physical or MAC address) 48 bits long, 6 octets, 12 hexadecimal digits. The first 6 hex numbers indicate the manufacture of the NIC (OUI), the last 6 are serial number of the NIC.
Layer 2 Tunneling Protocol (L2TP) (UDP ports 500 and 4500) Tunneling protocol similar to PPTP used to support Virtual Private Networks (VPNs). L2TP does not provide confidentiality or strong authentication by itself but is often used with IPsec to provide encryption. The combination of these two protocols is generally known as L2TP/IPsec. Published as proposed standard RFC 2661 August 1999. Wikipedia RFC 2661 Cisco
Layer 3 network layer of the OSI model. Wikipedia
Layer 4 Transport layer (TCP, UDP) Wikipedia
Layer 4 Switching Used to filter TCP and UDP packets before they reach Layer 3. HP proprietary.
Layer 5 session layer Wikipedia
Layer 6 presentation layer Wikipedia
Layer 7 (application layer) Wikipedia
Layer 8 user error Wikipedia
lazy instantiation (aka: lazy initialization) Not specifying a variable until it is needed for the first time. Wikipedia
LDAC Audio codec from Sony that allows up to 990 kbit/s at 24bit/96khz bit rate over Bluetooth. Website Wikipedia
LearnSecurity.org Website
leased line Private WAN infrastructure. Dedicated point-to-point connection leased from a service provider. Bandwidth is not shared with multiple customers. Examples include: T1, E1, T3, and E3. Can use multiplexing to transmit multiple conversations over different 64Kbps channels. Terminates on a CSU/DSU device. Wikipedia
least privilege concept A process should never be given more privilege than necessary.
legal and regulatory or compliance controls e.g. privacy laws, policies and clauses. Wikipedia
Leopard (Mac OS X 10.5) Wikipedia
less than (lt) Comparison operator. <, -lt,
less than or equal to (le) Comparison operator. <= or -le
Let's Encrypt Free, automated, and open Certificate Authority. Website Wikipedia
level 1 parent route a subnetted level 1 network route. Not an ultimate route.
level 1 route routing table entry with a subnet mask less than or equal to the classful mask of the network address. (Network route, Supernet route, Default route)
Level 10 Computer case made by Thermaltake and designed by BMW. Released August 2009. Amazon
level 2 child route a route that is a subnet of a classful network address.
LG G5 Smartphone from LG. Announced February 21, 2016. Released April 8, 2016. Website Wikipedia
LG G6 Smartphone from LG. Announced February 26, 2017. Website Wikipedia
LGA 1150 (LGA, 1150 pins, aka: Socket H3) CPU socket used with Intel microprocessors based on Haswell and Broadwell microarchitectures. Released in 2013. Wikipedia
LGA 1155 (LGA, 1155 pins, aka: Socket H2) CPU socket used with Intel microprocessors based on Sandy Bridge and Ivy Bridge microarchitectures. Released January 2011. Superseded by the LGA 1150. Wikipedia
LGA 1156 (LGA, 1156 pins, aka: Socket H, H1) CPU socket used with Intel microprocessors based on Nehalem and Westmere microarchitectures. Integrates the features traditionally located on a northbridge within the processor itself. Released in 2009. Superseded by the LGA 1155 socket. Discontinued in 2012. Wikipedia
LGA 1366 (LGA, 1366 pins, aka: Socket B) CPU socket used with high-end Intel microprocessors. The list includes the Core i7 (9xx series), Xeon (35xx, 36xx,55xx, 56xx series), and Celeron P1053. Released November 2008. Wikipedia
LGA 2011 (LGA, 2011 pins, aka: Socket R, LGA 2011-0) CPU socket used with high-end Intel microprocessors. The list includes Sandy Bridge-E (desktop Core i7-38xx, -39xx) and -EP (Xeon E5) as well as Ivy Bridge-E (desktop Core i7-48xx and -49xx) and -EP processors (Xeon E5 v2). Released on 14 November 2011. Replaced LGA 1366. Wikipedia
LGA 2011-1 (aka: Socket R2) CPU socket used with Intel microprocessors including Ivy Bridge-EX (Xeon E7 v2) and Haswell-EX (Xeon E7 v3) CPUs. Successor of LGA 1567. Released February 2014. Wikipedia
LGA 2011-v3 (aka: Socket R3, LGA 2011-3) CPU socket used with Intel microprocessors including Haswell-E (desktop, X99 chipset) and Haswell-EP (Xeon E5 v3) CPUs. Supports DDR4 memory. Released August 2014. Wikipedia
LGA 775 (LGA, 775 pins, aka: Socket T) CPU socket used by Intel microprocessors from 2004-2007. The list includes Prescott and Cedar Mill Pentium 4, Smithfield and Presler Pentium D, Core 2 Duo and Core 2 Quad. Released in 2004. Superseded by LGA 1156 (Socket H) and LGA 1366 (Socket B). Wikipedia
Librevault Open source zero-knowledge peer-2-peer file sync. Website GitHub
Light Emitting Diode (LED) Anode (+ long positive lead). Cathode (- short negative lead). Discovered by H. J. Round in 1907. Popularized by Nick Holonyak in 1962. Wikipedia YouTube (Make:)
Lights-Out Management (LOM) Another name for out-of-band management. Wikipedia
Lightweight Access Point Protocol (LWAPP)
Lightweight Directory Access Protocol (LDAP) (TCP and UDP port 389) Open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services. Wikipedia Ubuntu Documentation
Lightweight Extensible Authentication Protocol (LEAP) (deprecated) Basically EAP, with a password, in a TLS tunnel. Developed by Cisco Systems prior to the IEEE ratification of the 802.11i security standard. No longer used in favor of more secure protocols such as EAP-FAST, PEAP, or EAP-TLS. Wikipedia
LIKE SQL W3Schools
likelihood Level of certainty that something will happen, typically measured over the course of a year. Can be measured in two ways: quantitative or qualitative.
limited broadcast Broadcasts only to hosts on the local network (broadcast domain). Always use destination address o 255.255.255.255. Will not be forwarded by a router.
Line Print Terminal (LPT) Wikipedia
linear equations
| ax + b = c |
Link Access Procedure (LAP) Wikipedia
Link Access Procedure for Frame Relay (LAPF) Defines the header and trailer of Wikipedia
Link Access Procedure, Balanced (LAPB)
Link Aggregation Control Protocol (LACP) IEEE 802.3ad protocol used for EtherChannel Modes: On - forces interface to channel. LACP active - interface in active negotiation state. LACP passive - interface in passive negotiating state.
Link State Acknowledgements (LSAck) One of the OSPF protocol messages. Sent after a neighbor adjacency is established.
Link State Advertisement (LSA) Sent after a neighbor adjacency is established. LSAs are flooded to adjacent neighbors until all routers in the area have LSAs.
| type 1 | Router LSA. Also known as router link entries. All routers generate type 1 LSAs. Flooded only inside the area they came from, never go beyond ABR. Link ID is the router ID of originating router. |
| type 2 | Network LSA. Only exists for multi-access and nonbroadcast multi-access. Gives routers information about multi-access networks in the same area. Identify the routers and network addresses of multi-access links. Only generated by a DR. |
| type 3 | Summary LSAs. Advertises networks from other areas. ABR send type 3 LSAs to other areas. Routes are not summarized by default. Link state ID identified by network address. |
| type 4 | Advertise external networks into an OSPF routing domain. Only generated by ABRs. Identifies the ASBR and provides a route to it. |
| type 5 | AS external LSAs. Most summarized by default. |
| type 6 | Multicast OSPF LAS |
| type 7 | Defined for NSSAs |
| type 8 | External attributes LSA for BGP |
| type 9 | Opaque LSAs |
| type 10 | Opaque LSAs |
| type 11 | Opaque LSAs |
Link State Update (LSU) One of the OSPF protocol messages.
link-local address IPv4 addresses 169.254.0.0 to 169.254.255.255 (169.254.0.0/16) can be automatically assigned to the local host by the operating system in environments where no IP configuration is available. These addresses are not routable. The IPv6 address block FE80::/10 is reserverd for link-local unicast addressing. Wikipedia RFC 4291 (Link-Local IPv6 Unicast Addresses)
Link-Local Multicast Name Resolution (LLMNR) Based on DNS. Allows both IPv4 and IPv6 hosts to resolve addresses. Wikipedia
login shell Use echo $0 to determine if you are in a login shell. Output will either be "-bash" (login shell) or just "bash" non-login shell.
Line Printer (lpr) Command that sends a file to the printer. Exameple: lpr foobar CUPS Microsoft
Line Printer Daemon (LPD) Wikipedia
Linear Tape-Open (LTO) Magnetic tape data storage technology. Maximum capacity of 12 TB with the 8th generation as of 2017. LTO-1 released in 2000. Wikipedia
Link-State Database (LSDB) One of the three OSPF databases. Contains the topology table.
Link-State Request (LSR) One of the OSPF protocol messages.
link-state routing protocol Has a complete map of the network. Computes the network topology from its perspective. Requires more hardware resources. OSPF is an example of a link-state protocol.
Linksys E2000 Default: 192.168.1.1 admin admin Website User Guide
Linus Torvalds Developer of Linux. Wikipedia
Linux Operating system based off of UNIX. Written in C. Wikipedia
Linux Information Project (LINFO) Website
Linux-Apache-MySQL-PHP (LAMP) Solution stack. Wikipedia Ubuntu Community
Lion (OS X 10.7) Released July 20, 2011. Wikipedia
Liquid Crystal Display (LCD) Wikipedia
Lisa Su CEO of AMD. Wikipedia
litigation hold (LH) Website Wikipedia
Live CD OS installation that can boot from an optical disc. Wikipedia
Live File System Microsoft's First appeared in Windows Vista. Wikipedia Microsoft
Live Tile Presents information such as the weather or email notifications without needing to launch an app. Wikipedia
LLVMpipe Wikipedia
lm-sensors CLI tool that can monitor temperature, fan speed, and voltage. Ubuntu Community Websiste
load balancer (aka: content switch) distributes incoming requests accross multiple servers. All servers contain the same data. Wikipedia
Load-Reduced Dual In-Line Memory Module (LRDIMM)
Local Area Network (LAN) A network that is in a small geographical area such as home or office. Wikipedia
Local Area Network Denial (LAND) Type of DoS attack. Wikipedia
Local Connector (LC) (aka: little connectors) Mini Form Factor (MFF) fiber-optic connector popular for use with Fiber-Channel adapters, fast SANs, and Gigabit Ethernet. Developed by Lucent Technologies. Wikipedia
local host Administrative distance is 0.
Local Loop The physical cable that connects the CPE to the CO of a service provider. (The last mile.)
Local Management Interface (LMI) Wikipedia
Local Security Authority Subsystem Service (LSASS) lsass.exe Responsible for enforcing the security policy on Windows. Wikipedia
Lock It Down Locks your 'Content Sensitive' files and folders quickly and professionally using 128-bit Thayer encryption, which make it unable for others to view or use them without your consent, which results in a clean conscience and instant peace of mind. Website
logic bomb Wikipedia
logic error When code runs without error Wikipedia
logic gate Wikipedia
logical Address (OSI Network Layer 3) Wikipedia
logical AND operator && Returns the boolean value true if both sides of the operator are true. Microsoft Docs
Logical Link Control (LLC) A Layer 2 protocol. Wikipedia
Logical Unit Number (LUN) 64 bit address for a drive. Used by SCSI.
login local Uses a username and password from a local database to login.
Logitech Unifying One tiny receiver for up to six Unifying devices. Website Logitech Support
Long-Haul network Service providers use long-haul terrestrial optical fiber networks to connect long distances.
Long-Term Evolution (LTE) A standard for wireless communication. Wikipedia
Long-term Servicing Branches (LTSB) Windows update/support branch for Windows 10 Education and Enterprise. Wikipedia
lookup field Allows the user to select from a list of values when updating the contents of a field. Microsoft Office Training
loopback address Can ping 127.0.0.1 to see if NIC is working. Is also a special address a host can use to direct traffic to themselves. Additional loopback addresses include 127.0.0.0 through 127.255.255.255 for IPv4. IPv6 also has ::1/128 and just ::1 for loopback addresses. Wikipedia PC Magazine
lorem =lorem(x,y) Adds lorem text to a word document.
lottery numbers (lotto numbers)
Lotus Notes Corporate email system. Now called IBM Notes. Wikipedia
Low Level Virtual Machine (LLVM) Wikipedia
low risk May be accepted without mitigation or requires little mitigation.
low-frequency oscillator (LFO) Wikipedia
Lowest Common Denominator (LCD) The product of all products different factors raised to the greatest power. Wikipedia
ls UNIX command that displays the contents of a directory. Wikipedia