A packet-filtering firewall installed on a TCP/IP-based network typically functions at the TCP level.

The reserved name localhost always corresponds to the IP address 127.0.0.1 so that a local machine can always be referenced by this name.

Answer the following statement true (T) or false (F)

Modify the original Example1 code so that the receiver loops indefinitely to receive and output datagrams. Recompile. Then (i) start the receiver, (ii) execute the sender, sending a message “message 1”, (iii) in another window, start another instance of the sender, sending a message “message 2”. Does the receiver receive both messages? Capture the output. Draw a picture to describe the IPC involved in the experiment.

This exercise guides you through experiments with connectionless datagram socket via code sample Example1. As a start, it is recommended that you run both programs on one machine, the host name of which you may refer to as “localhost”, as in the command “java Example1Sender localhost 12345 hello” to execute Example1Sender. You may optionally repeat the exercises by running the programs on separate machines, assuming that you have access to such machines.