Interview Questions on Network - TCP/IP Model

1. What are the differences between OSI model and TCP/IP model?

The only difference in the name of OSI network Layer compared to TCP/IP Internet Layer. The upper three layers of the OSI reference model (application, presentation, and session—Layers 7, 6, and 5) define functions that all map to the TCP/IP application layer.

2. What are all the layers exist in TCP/IP model?

1. Application Layer
2. Transport Layer
3. Internet Layer
4. DataLink Layer
5. Physical Layer

3. Explain about Internet Layer ?

The Internet layer is responsible for addressing, packaging, and routing functions.

4. What are all the protocols exist in IP Layer?

The core protocols of the Internet layer are IP, ICMP, and IGMP.
The Internet Protocol (IP): It is a routable protocol responsible for IP addressing, routing, and the fragmentation and reassembly of packets.
The Internet Control Message Protocol (ICMP): It is responsible for providing diagnostic functions and reporting errors due to the unsuccessful delivery of IP packets.
The Internet Group Management Protocol (IGMP): It is responsible for the management of IP multicast groups.

5.Explain Transport Layer?

The Transport layer (also known as the Host-to-Host Transport layer) is responsible for providing the Application layer with session and datagram communication services.

6. Explain the protocols exist in Transport Layer?

The core protocols of the Transport layer are : TCP and UDP.
Transmission Control Protocol(TCP): provides a one-to-one, connection-oriented, reliable communications service. TCP is responsible for the establishment of a TCP connection, the sequencing and acknowledgement of packets sent, and the recovery of packets lost during transmission.

User Datagram Protocol(UDP): provides a one-to-one or one-to-many, connectionless, unreliable communications service. UDP is used when the amount of data to be transferred is small (such as the data that would fit into a single packet), when the overhead of establishing a TCP connection is not desired or when the applications or upper layer protocols provide reliable delivery.

7. What are the Differences between TCP and UDP?

TCP is COnnection Oriented and reliable protocol.
UDP is Connection less and unreliable protocol.

8. Explain about Application Layer?

The Application layer provides applications the ability to access the services of the other layers and defines the protocols that applications use to exchange data.

9. Explain about protocols exist in Application Layer?

The most widely-known Application layer protocols are :
The Hypertext Transfer Protocol (HTTP): it is used to transfer files that make up the Web pages of the World Wide Web.
The File Transfer Protocol (FTP): it is used for interactive file transfer.
The Simple Mail Transfer Protocol (SMTP): It is used for the transfer of mail messages and attachments.
Telnet (a terminal emulation protocol):It is used for logging on remotely to network hosts.