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LAN
LANs (Local Area Networks) are networks that serve users within specific geographical areas, such as in
a company building. LANs are comprised of servers, workstations, a network operating system, and
communications links such as the router.
MAC ADDRESS
A MAC address is a unique serial number burned into hardware adapters, giving the adapter a unique
identification.
METRIC
A number that indicates how long a packet takes to get to its destination.
MTU
MTU (Maximum Transmission/Transfer Unit) is the largest packet size that can be sent over a network.
Messages larger than the MTU are divided into smaller packets.
NAT
NAT (Network Address Translation - also known as IP masquerading) enables an organization to present
itself to the Internet with one address. NAT converts the address of each LAN node into one IP address
for the Internet (and vice versa). NAT also provides a certain amount of security by acting as a firewall by
keeping individual IP addresses hidden from the WAN.
(NETWORK) ADMINISTRATOR
The network administrator is the person who manages the LAN within an organization. The
administrator's job includes ensuring network security, keeping software, hardware, and firmware
up-to-date, and keeping track of network activity.
NTP
NTP (Network Time Protocol) is used to synchronize the realtime clock in a computer. Internet primary
and secondary servers synchronize to Coordinated Universal Time (UTC).
PACKET
A packet is a portion of data that is transmitted in network communications. Packets are also sometimes
called frames and datagrams. Packets contain not only data, but also the destination IP address.
PING
Ping (Packet INternet Groper) is a utility used to find out if a particular IP address is present online, and is
usually used by networks for debugging.
PORT
Ports are the communications pathways in and out of computers and network devices (routers and
switches). Most PCs have serial and parallel ports, which are external sockets for connecting devices
such as printers, modems, and mice. All network adapters use ports to connect to the LAN. Ports are
typically numbered.
PPPOE
PPPoE (Point-to-Point Protocol Over Ethernet) is used for running PPP protocol (normally used for
dial-up Internet connections) over an Ethernet.
PREAMBLE
Preamble refers to the length of a CRC (Cyclic Redundancy Check) block that monitors communications
