code: public static String getMacForLocalIp(InetAddress addr) throws SocketException, NoMacAddressException, NoInterfaceException
  	{
  		return getMacFor(getInterfaceForLocalIp(addr));
  	}
docs: Given an InetAddress, determines the MAC Address (hardware address) of the corresponding interface
  
  @param addr
  The IP address
  
  @return The MAC Address
  
  @throws SocketException
  If we couldn't get the interface
  @throws NoMacAddressException
  If the interface doesn't have a mac address specified