There appears to be a socket leak in both DatagramSocket and MulticastSocket constructors. Both classes have constructors that create a socket and then attempt to bind. The bind can fail with a variety of exceptions none of which are caught by the constructor. Thus, the actual system socket that was allocated by impl.create() is never closed.
My fix was to wrap a try-finally around the bind call and call close() if isBound is false. public DatagramSocket(SocketAddress bindaddr) throws SocketException { // create a datagram socket. createImpl(); if (bindaddr != null) { try { bind(bindaddr); } finally { if( !isBound() ) close(); } } } Tom Salter Unisys Corporation