4.9.4 TCP/IP Flashcards
What is a protocol?
Set of pre-agreed rules that defines how data is transmitted over a network
What does TCP/IP stand for?
Transmission control protocol / internet protocol
What is the application layer of the TCP/IP protocol do?
Decides appropriate protocols depending on users choice of output.
eg. HTTP (HyperText), SMTP (Standard Mail) and FTP (File)
What is the transport layer of the TCP/IP protocol do?
Splits data into packets , each packet assigned source and destination port numbers and sequence numbers (position within packets for reconstruction)
eg. TCP (Transmission control)
What is the Network layer of the TCP/IP protocol do?
Encapsulate data with source and final destination IPs
What is the Link layer of the TCP/IP protocol do?
Encapsulate data with source and destination MAC’s (For next router -hop- not final destination). Link header stripped at each router and new source and destination MAC’s are assigned.
What is a MAC address?
Address embedded in NIC used to identify devices within a network
What is a socket in the context of TCP/IP and routing packets?
Combination of an IP address and port number used for receiving and sending data over a network
What is a socket in the context of TCP/IP and routing packets?
Combination of an IP address and port number used for receiving and sending data over a network
What is a port number in the context of TCP/IP and routing packets?
16 bit number used to identify the process which data is sent/received by a host device. They distinguish different apps running on the same device.
What is a packet?
Small section of data split into equal pieces to be transferred over a network
What does HTTP stand for ?
Hyper-text transfer protocol
How does HTTP work ?
Client sends an HTTP request for a webpage to server. Server receives request and sends a http response encapsulating web page to client.
What is HTTPS ?
HTTP Secure
How does HTTPS keep your data private ?
Encrypts it by providing a digital certificate containing encryption key. and only the authorised server possesses the corresponding key to decrypt it.
What does FTP stand for ?
File transfer protocol
What does FTP do and how is it used ?
Move files between two devices through a client server application like downloading / uploading software or music.
What does POP3 stand for ?
Post office protocol
What does IMAP stand for ?
Internet message access protocol
What does POP3 do ?
Retrieves emails by downloading them onto a clients device and deletes them from the server
What does IMAP do ?
Retrieves emails by creating copies on the local client device and synchronises any deletion between the server and the device (can manage btwn devices).
What does SMTP stand for ?
Simple mail transfer protocol
What does SMTP do and how does it work ?
Sends emails by transferring email from clients device to server then forwards it to the recipients mail server if on a different domain.
What is SSH
Secure shell provides an encrypted connection for remote access to another device by encrypting messages btwn the device and server.
