#!/bin/bash

i=1; 
while [ $i -le 255 ]; do 
#echo $i; i=$[$i+1]
  ping 192.168.137.$i -c1 >> aa1
  if test $? -eq 0; then
    echo $i >> aaaa
  fi
#ping 192.168.137.107 -c1
  i=$[$i+1]
done