4.9.4 TCIP/IP Protocol Flashcards
What is the TCIP/IP Protocol stack and what layers are there?
Remember ATNL
1) A stack of networking protocols that combine as 4 connected layers which pass incoming and outgoing data packets up and down layers of network communication
1) Application Layer
2) Transport Layer
3) Network Layer
4) Link Layer
What is the function of the application layer?
1) Top of the stack
2) Uses protocols related to the application to transmit data over a network
What is the function of the Transport layer?
1) Uses Transmission control protocol (TCP) to establish and end to end connection with the recipient computer
2) Data is split into packets and labelled with the:
1) Packet number
2) Total number of packets
3) Port number to ensure it is handled by the correct application on the recipient computer
What is the function of the Network layer?
1) Adds the source and destination IP addresses
2) Routers use these IP addresses to forward packets to the destination
3) Combining the IP address and the port number forms a socket that specifies the device that the packet is to be sent to and the application being used on that device
What is the function of the link layer?
1) Controls physical connections between pieces of hardware in a network, it Adds MAC addresses to packets which it receives from the network layer
What is the role of MAC (Media Access Control) addresses?
1) MAC is a unique 12-digit hexadecimal code that is hardcoded on every NIC (Network Interface Card) during the manufacture
2) This uniquely identifies a particular device anywhere in the world so that data packets can be routed directly to them
Explain what the FTP protocol is used for (Port 20 and 21)
1) Port 20 and 21
2) Used to transfer files between two computers
3) Used to remotely access a computer/server
4) Transfer files to the server first and then from the server to the recipient’s computer
Explain what the SMTP protocol is used for (Port 25)?
1) Port 25
2) Used to send emails from email client to email server
3) Simple Mail Transfer Protocol
Explain what the POP3 protocol is used for (Port 110)?
1) Port 110
2) Used to retrieve emails from email servers
3) Automatically remove emails from the server once they are accessed locally
Explain what the SSH protocol is used for (Port 22)?
1) Port 22
2) Used for remotely accessing and managing a computer
3) uses public-key encryption that requires a digital certificate to authenticate the user
Explain what the HTTP protocol is used for (Port 80)?
1) Port 80
2) Used to hold web pages in text form by a web server which they can deliver to clients
Explain what the HTTPS protocol is used for (Port 443)?
1) Port 443
2) Same function as HTTP but encrypts the information during transfer
Explain how an FTP client software works in terms of anonymous and non-anonymous access?
1) FTP Software client at the top of the protocol
2) User actions generate FTP commands
3) Files are transferred by dragging from one area to another
4) Most FTP servers require a username and password to access but some sites can be set up for anonymous use without any login details
How is SSH used for remote management?
1) uses public-key encryption that requires a digital certificate to authenticate the user
2) Used by network administrators to remotely manage business servers using commands
Explain how SSH can be combined with other application-level protocols to create loopholes?
1) Commbinign SSH with other application-level protocols can create a ‘tunnel’ through port 22 where HTTP, POP3 or SMTP requests can operate
2) This allows for network restrictions to be bypassed