To compile the server do:
$ javac PingServer.java
To run the server do:
$ java PingServer <port number> // Use registered ports i.e. b/w 1024 and 49151.
ex : java PingServer 1026
If you get class not found error do:
$ java -classpath . PingServer <port number>
To compile the Client do:
$ javac PingClient.java
To run the Client Pinger do:
$ java PingClient <Host Name> <port number> // Port number must be same as the server port number
ex : java PingClient 127.0.0.1 1026
If you get class not found error do:
java -classpath . PingClient <Host Name> <port number>
Remaining files can be done in the same way as above.
Note : UDP Server must be running to get a response, so run both Server and Client simultaneously.