Firewall: It is a device that blocks or allows traffic based on established rules
Five layer model: A model used to explain how network devices communicate. This model has five layers that stack on top of each other: Physical, Data Link, Network, Transport, and Application
Flag field: It is used to indicate if a datagram is allowed to be fragmented, or to indicate that the datagram has already been fragmented
Fragmentation offset field: It contains values used by the receiving end to take all the parts of a fragmented packet and put them back together in the correct order
Fragmentation:The process of taking a single IP datagram and splitting it up into several smaller datagrams
Frame check sequence: It is a 4-byte or 32-bit number that represents a checksum value for the entire frame
FTP: An older method used for transferring files from one computer to another, but you still see it in use today
Full duplex: The capacity of devices on either side of a networking link to communicate with each other at the exact same time
H
Half-duplex:It means that, while communication is possible in each direction, only one device can be communicating at a time
Handshake: A way for two devices to ensure that they're speaking the same protocol and will be able to understand each other
Header checksum field: A checksum of the contents of the entire IP datagram header
Header length field: A four bit field that declares how long the entire header is. It is almost always 20 bytes in length when dealing with IPv4
Hexadecimal: A way to represent numbers using a numerical base of 16
Hub: It is a physical layer device that broadcasts data to everything computer connected to it
I
IANA: The Internet Assigned Numbers Authority, is a non-profit organization that helps manage things like IP address allocation
Identification field: It is a 16-bit number that's used to group messages together
