Active Directory OSI seven-layer model

1. The OSI reference model divides the network into seven layers. What are the layers from bottom to top?
   Answer: Physical layer, data link layer, network layer, transport layer, session layer, presentation layer, application layer

2. What are the main functions of the Network Layer?
   Answer: Realize the transmission of data from the source to the destination.

3. What are the main functions of the Transport Layer?
   Answer: Realize data communication between user processes on different hosts in the network.

4. What are the common protocols in the network layer?
   Answer: ARP, RARP, ICMP, IGMP

5. The figure shows the correspondence between the TCP/IP five-layer model and the OSI seven-layer model.
   Answer:

6. What are the rules that must be followed between the sender and receiver at the same level?
   Answer: Agreement

7. Which layer of the OSI reference model are TCP and UDP?
   Answer: Transport layer

8. In the process of data transmission, where do data frames and bit streams appear respectively?
   Answer: Data link layer, physical layer

9. Which layer of network equipment are firewalls, routers, and switches?
   Answer: Transport layer, network layer, data link layer