Java In A Nutshell, 5th Edition

An exception of this type may be thrown by a send( ) or receive( ) call on a DatagramSocket if the connect( ) method of that socket has been called, and if the connection attempt resulted in an ICMP "port unreachable" message.

public class PortUnreachableException extends SocketException { // Public Constructors public PortUnreachableException ( ); public PortUnreachableException (String msg ); }