Node: Any device connected to a network. On most networks, each node will typically act as a server or a client
Non-routable address space: They are ranges of IPs set aside for use by anyone that cannot be routed to
NS record: It indicates other name servers that may also be responsible for a particular zone
NTP servers: Used to keep all computers on a network synchronized in time
O
Octet: Any number that can be represented by 8 bits
Options field: It is sometimes used for more complicated flow control protocols
Organizationally Unique Identifier (OUI): The first three octets of a MAC address
OSI model: A model used to define how network devices communicate. This model has seven layers that stack on top of each other: Physical, Data Link, Network, Transport, Session, Presentation, and Application
P
Padding field: A series of zeros used to ensure the header is the correct total size
Patch panel: A device containing many physical network ports
Payload: The actual data being transported, which is everything that isn't a header
Physical layer: It represents the physical devices that interconnect computers
Pointer resource record: It resolves an IP to a name
Port forwarding: A technique where specific destination ports can be configured to always be delivered to specific nodes
Port preservation:A technique where the source port chosen by a client, is the same port used by the router
Port: It is a 16-bit number that's used to direct traffic to specific services running on a networked computer
Preamble: The first part of an Ethernet frame, it is 8 bytes or 64 bits long and can itself be split into two sections
Presentation layer: It is responsible for making sure that the unencapsulated application layer data is actually able to be understood by the application in question
