#!/usr/bin/perl -w

use strict;

while (<DATA>)
{
  if (/\s(159\.230\.\d+\.\d+)/)
  {
    print $1,"\n";
  }
}

__DATA__
network-object 159.230.123.000 255.255.224.0
network-object 159.230.234.000 255.255.252.0
network-object 159.230.111.000 255.255.255.0
network-object host 159.230.101.000
network-object host 159.230.200.000
network-object host 159.230.6.000