Selector.open() uses two TCP ports on Windows

Question

As part of a security review, we are monitoring the ports opened by our application (which uses NIO) using TCPView on Windows Vista Business with sp1.
I ran the NIO test below.
public class NioSelectorMain {
public static void main(String[] args) throws Exception {
Selector selector = Selector.open();
System.out.println(selector);
Thread.sleep(Integer.MAX_VALUE);
Example output is:
sun.nio.ch.WindowsSelectorImpl@b1c5fa
TCPView showed the following two ports opened - the numbers change each time obviously, but there are always two ports.
javaw.exe:8224     TCP     aled-PC:50741     localhost:50742     ESTABLISHED     
javaw.exe:8224     TCP     aled-PC:50742     localhost:50741     ESTABLISHED     
I've tried this with sun jdk1.6.0_05 and jdk1.5.0_14. When running the same test on Linux, no ports are opened.
Why are these ports used, and is there any way to either prevent them from being opened or to specify which ports should be used?
Thanks in advance, Aled

Answer 1

Thanks for the very prompt reply!
or to specify which ports should be used?Why would you want to do that?Our enterprise customers would like to know which ports will be used so that they can lock down the machine as much as possible, and can better detect malicious programs/usage.
I presume by "why would you want to do that" that it's not possible?