Socket bind fails when port in use as rootuser but succeeds as nonroot user

Question

Hi All,
I have a prerequiste to check if a port is busy/already bound on Solaris 11.
java version : java version "1.6.0_24"
os : SunOS 5.11 11.0 i86pc i386 i86pc
The code snippet is as follows.
=====================================================================================
arrayOfInetAddress = InetAddress.getAllByName("example.com");
try
for (int j = 0; j < arrayOfInetAddress.length; j++)
System.out.println(" Trying for host : " + arrayOfInetAddress[j] + " and port : " + i);
localServerSocket = new ServerSocket(i, 0, arrayOfInetAddress[j]);
localServerSocket.close();
System.out.println("Port = " + i + " passed by the user is free");
catch (IOException localIOException)
System.out.println("isPortFree:Port=" + i + " is busy. Exception ioe=" + localIOException.getMessage());
localIOException.printStackTrace();
====================================================================
when i run this application as a root user it correctly complains saying the port is already bound
java CheckFreePort 9876
java.net.BindException: Address already in use
but when i run it as a non root user it says the port is free which is incorrect.
java CheckFreePort 9876
Port = 9876 passed by the user is free
what could be the reason that bind succeeds even though the port is in use as a non root user.
thanks,
Prakash

Answer 1

there is an em agent which is listening on this port.
=========================================
# su root
# netstat -naP tcp|grep 9876
*.9876 *.* 0 0 128000 0 LISTEN
*.9876 *.* 0 0 128000 0 LISTEN
#java CheckFreePort 9876
java.net.BindException: Address already in use
=========================================
===========================================
# su oracle
# netstat -naP tcp|grep 9876
*.9876 *.* 0 0 128000 0 LISTEN
*.9876 *.* 0 0 128000 0 LISTEN
#java CheckFreePort 9876
Port = 9876 passed by the user is free
============================================
Is this something to do with the privileges of the non root user ?