Demarcate: To set the boundaries of something
Demarcation point: Where one network or system ends and another one begins
Demultiplexing: Taking traffic that's all aimed at the same node and delivering it to the proper receiving service
Destination MAC address: The hardware address of the intended recipient that immediately follows the start frame delimiter
Destination network: The column in a routing table that contains a row for each network that the router knows about
Destination port: The port of the service the TCP packet is intended for
DHCP discovery: The process by which a client configured to use DHCP attempts to get network configuration information
DHCP: A technology that assigns an IP address automatically to a new device. It is an application layer protocol that automates the configuration process of hosts on a network
DNS zones: A portion of space in the Domain Name System (DNS) that is controlled by an authoritative name server
Domain Name System (DNS): A global and highly distributed network service that resolves strings of letters, such as a website name, into an IP address
Domain name: A website name; the part of the URL following www.
Domain: Used to demarcate where control moves from a top-level domain name server to an authoritative name server
Dotted decimal notation: A format of using dots to separate numbers in a string, such as in an IP address
Duplex communication:A form of communication where information can flow in both directions across a cable
Dynamic allocation: A range of IP addresses is set aside for client devices and one of these IPs is issued to these devices when they request one
Dynamic IP address: An IP address assigned automatically to a new device through a technology known as Dynamic Host Configuration Protocol
E
ESTABLISHED: Status indicating that the TCP connection is in working order, and both sides are free to send each other data
