private byte[] ipWithSubnetMask(byte[] ip,byte[] subnetMask){
  int ipLength=ip.length;
  byte[] temp=new byte[ipLength * 2];
  System.arraycopy(ip,0,temp,0,ipLength);
  System.arraycopy(subnetMask,0,temp,ipLength,ipLength);
  return temp;
}

private byte [ ] ipWithSubnetMask ( byte [ ] ip , byte [ ] subnetMask ) { int ipLength = ip . length ; byte [ ] temp = new byte [ ipLength * 2 ] ; System . arraycopy ( ip , 0 , temp , 0 , ipLength ) ; System . arraycopy ( subnetMask , 0 , temp , ipLength , ipLength ) ; return temp ; }
concatenates the ip address with its subnet mask .
