get lost host num

lost.rb

#!/usr/bin/env ruby

require 'socket'

def crooms
{
  '301' => ['192.168.7.1','192.168.7.54'],
  '303' => ['192.168.5.1','192.168.5.51'],
  '304' => ['192.168.6.1','192.168.6.48'],
  '401' => ['192.168.1.1','192.168.1.51'],
  '404' => ['192.168.4.1','192.168.4.51'],
  '502' => ['192.168.11.1','192.168.11.54'],
  '503' => ['192.168.9.1','192.168.9.54']
}
end

def unreachables(room)
  start = crooms[room][0]
  stop  = crooms[room][1]
  #result = `nmap #{start}-#{stop} -n -sP | grep report | awk '{print $5}'`
  #if use nmap , stop will be last section of stop
  result = `fping -ugq #{start} #{stop} | awk -F '.' '{print $4}'`
  return result
end

server = TCPServer.new(2000)
while(client=server.accept)
  room = client.gets.chomp.strip  
  if crooms.keys.include?(room.to_s)
    client.puts unreachables(room).gsub("\n"," ")
  else
    client.puts "wrong"
  end
  client.close
end