Question

Besides IP address, what is the other major component that defines a socket? Compare the three types of sockets that are mainly used for programming (e.g., Java programming)? What is a loopback and when is it used? Imagine that a host with IP address 150.55.66.77 wishes to download a file from a default web server at IP address 202.28.15.123. Give an example of a valid socket pair for a connection between this pair of hosts.

Answer 1

The application port number is another major component which defines the socket. An application port number is used to identify within the destination or source system which two application are going to communicate or have messages for each other. The loopback address is the designated ip address(127.0.0.1) which helps IT engineers to test network application without worrying about driver and hardware failures, loopback address does not require any data or hardware to work its functionality is taken care by software only

the host 150.55.66.77 will use the file transfer protocol to download the file from web server. The file transfer protocol uses port number 21 . The webserver 202.28.15.123 will use a ephemeral port number 3522 to give a response for requests hence a valid socket pair is

Socket Pair

(150.55.66.77:21 , 202.28.15.123:3522)