Definitions Flashcards
TCP/IP
Transmission Control Protocol/Internet Protocol
TCP/IP is a set of rules (protocols) governing communications among all computers on the Internet. More specifically, TCP/IP dictates how information should be packaged (turned into bundles of information called packets), sent, and received, and how to get to its destination.
DHCP
Dynamic Host Configuration Protocol
DHCP is a protocol used to assign an IP address to a computer or device connected to a network automatically. Routers, switches, or servers that use DHCP to assign addresses to other computers can make setup and management easier for the network administrator.
On a home network, DHCP can be set up by purchasing a home router, wireless router, or switch with NAT/DHCP and connecting each computer to it. If the network has a firewall, ports 67 and 68 need to be open for devices to function properly.
DNS
Domain Name System
Stands for “Domain Name System.” Domain names serve as memorizable names for websites and other services on the Internet. However, computers access Internet devices by their IP addresses. DNS translates domain names into IP addresses, allowing you to access an Internet location by its domain name.
DNS is a service that receives a request containing a domain name hostname and responds with the corresponding IP address.
UDP
User Datagram Protocol and defined in RFC 768, UDP is a network communications protocol. Also called UDP/IP, it is an alternative to TCP/IP that sacrifices reliability for speed and simplicity.
Like TCP, UDP transfers packets using IP (Internet Protocol). However, it differs in what data the packets contain, and how the packets are handled by the sender and receiver.
Differences between TCP and UDP
Unlike TCP, UDP does not provide for error checking, or recovery of packets that were lost in transit.
TCP is connection-oriented. The protocol requires that a communication session is established, and that the sender and receiver agree about what data was transferred. When TCP packets are received and pass an error check, the receiver responds with an acknowledgement. If TCP packets are corrupted or lost in transit, the receiver does not send an acknowledgement, and the sender eventually re-sends those packets.
UDP is connectionless. The receiver can request and listen for UDP packets, but no session is established (there is no “beginning” or “end,” data is merely sent and received). If UDP packets are corrupted or lost in transit, the receiver may not be aware of the error. The receiver does not report errors to the sender, or acknowledge that data was received.
HTTPS
Hypertext Transfer Protocol Secure (HTTPS) is a secure connection-oriented protocol that runs over port 443.
NetBIOS
Network Basic Input/Output System
NetBIOS was developed by IBM, Microsoft, and Sytek. NetBIOS allows computers and applications to communicate with network hardware, and allows data to transmit properly over a network. For example, Microsoft Windows computers that are named in a workgroup and not a domain use NetBIOS names, which are converted to IP addresses.
NetBIOS commonly communicates on ports 137, 138, and 139. If your firewall blocks any of these ports you may get errors when your computer communicates with another computer that utilizes NetBIOS (e.g., Microsoft Windows). To prevent these errors or warnings, you must provide access on these ports.
SOHO
Short for small office/home office, SOHO is a business where users work at their home or in a small office.
NIC
Short for network interface card, the NIC is also called an Ethernet card and network adapter. A NIC is a computer expansion card for connecting to a network (e.g., home network or Internet) using an Ethernet cable with an RJ-45 connector.
In a desktop computer, the network card is often located near the USB ports on the back if it’s an onboard version. If it’s a separate network card expansion card (not onboard), it usually is on the back of the computer, near the bottom, taking up a PCI slot.
In a laptop, the network card is integrated into the motherboard. The network port is usually on the side on the laptop, or it may be on the back. If you cannot find a network port on your laptop, it may only have a wireless network connection. You can purchase a network card for laptops, which is installed into a PC card slot on the side of the laptop, if available.
MAC
Short for Media Access Control, or MAC address. Known as a physical address and hardware address whose number is uniquely formatted in hexadecimal format and given to each computer or network device on a computer network.
MAC addresses can be 48-bit or 64-bit numbers divided into two parts. A unique three-byte OUI (Organizationally Unique Identifier) identifies the device’s manufacturer and must be purchased from the IEEE. The manufacturer assigns the remaining three or five bytes. After the number is generated, it’s considered burned into the firmware of the network access hardware.
Because a MAC address is a unique address, devices on a network do not share the same MAC address.
Example of a MAC address
D4-BE-D9-8D-46-9A
Note
IoT
Internet of Things (IoT) is an idea of all objects in the world being uniquely identifiable, tracked, and connected to the Internet. If every object could be identified and tracked businesses could more efficiently manufacture products, as they would know how much inventory they have available and what needs to be ordered. People could find whatever they needed very quickly and easily by executing a search of the Internet of things and locate the item or person they need. The world would be forever changed and, to the hope of many people, made better.
Back of RFID
The first technology considered to be the beginning of the Internet of Things was RFID. Devices with RFID had a unique identifier and could be tracked like inventory. Computer systems can identify where RFID devices are, within a specified range of distance. Security systems often use RFID devices for tracking employees in buildings or equipment in warehouses and can give a virtual map of everything in a building or warehouse.
People envision the future, the Internet of things, as a place where even people could be uniquely identified by some form of device or computer chip. It can provide for a safer world, but it could also create larger paranoia, where people think they are being watched. At the rate technology is advancing and shrinking in size, the Internet of things is not far fetched and could be closer than we think.
RFID
Short for radio frequency identification, a RFID is a small tag that enable a store or company to keep track of inventory.
NFC
Near-field communication (NFC) requires devices to be within about 10 centimeters of each other to transmit data.
IDS
Short for intrusion detection system, IDS is a security measure that notifies an administrator when a system policy is being violated. Such violations may include the unauthorized opening of a hardware device, or a network resource used without permission. For example, a corporate computer may be equipped with an IDS system that sounds an alarm and alerts the IT staff. IDS is helpful for companies concerned about employees opening a computer and stealing internal components such as RAM or installing something in the computer without authorization.
IPS
IPS is short for intrusion prevention system. An IDP is a device that helps monitor, log, and block malicious activity on a network. IPS works by looking for known signatures in an attack and watching for abnormal activity. When triggered, the system can immediately block the attack and alert an administrator.
UTM
Short for Unified Threat Management, a UTM is a networking device or software program that helps reduce the complexity of securing a network. It accomplishes this by including an anti-malware, content filter, firewall, intrusion detection, and spam protection into a single package. Usually, a UTM is used in a corporate environment. It may also feature application awareness, identity-based access control, QoS, load balancing, SSL inspection, and SSH inspection.
URL
Also known as an internet address or web address, a URL (Uniform Resource Locator) is a URI and standardized naming convention for addressing documents accessible over the Internet and Intranet. The URL makes it possible for a computer to locate and open a web page on a different computer on the Internet. An example of a URL is https://www.computerhope.com, the URL for the Computer Hope website.
SNMP
Short for Simple Network Management Protocol, SNMP was first introduced in 1988 and is a query, command, and response protocol. SNMP examines and changes configuration parameters of LAN and WAN connected repeaters, bridges, routers, switches, and other devices connected to a network.
SNMP defaults to use port 161.
SCADA
Supervisory Control and Data Acquisition (SCADA) systems consist of both hardware and software.
RADIUS
Remote Authentication Dial-In User Service (RADIUS) is a protocol for authentication servers that encrypts transmissions between client and server.
PCI
Short for peripheral component interconnect, PCI was introduced by Intel in 1992. The PCI bus came in both 32-bit (speed of 133 MBps) and 64-bit versions and was used to attach hardware to a computer. Although commonly used in computers from the late 1990s to the early 2000s, PCI has since been replaced with PCI Express.
Examples of PCI devices
Modem
Network card
Sound card
Video card
UEFI
Short for Unified Extensible Firmware Interface, UEFI is an upgrade to the traditional computer BIOS that Intel started developing as EFI. UEFI is an update that includes improved boot times, better security with cryptography, and better support for the hardware found in today’s computers.
UEFI is compatible with the standard hard drive partition format, which utilizes an MBR (master boot record) and the GPT (GUID partition table) partition format. Linux and Windows operating systems can utilize UEFI.
DDR3
Short for double data rate three, DDR3 is a type of DRAM (dynamic random-access memory) released in June 2007 as the successor to DDR2. DDR3 chips have bus clock speed of 400 MHz up to 1066 MHz, range in size from 1 to 24 GB, and consume nearly 30% less power than their predecessors. DDR3 RAM sticks for a desktop computer have 240 pins. For a laptop computer, DDR3 RAM sticks have 204 pins.
