Fastest way to ping a network range and return responsive hosts?

Question

Constraints:
1. Speed matters.
2. I am allowed to ping once.

I'm debating whether to use Python or shellscripting. Is there a method faster than bash?

Here is the current code,

for ip in $(seq int1 int2); do
    ping -c 1 xxx.xxx.xxx.$ip | grep "bytes from" &
done

Anything faster than this?

Answer 1

You should use nmap:

nmap -T5 -sn 192.168.0.0-255
nmap -T insane -sn 192.168.0.0-255 # same as above but w/named template

The -T 5/insane option uses the "insane" template, which:

insane mode assumes that you are on an extraordinarily fast network or are willing to sacrifice some accuracy for speed. -T4 (aggressive) prohibits the dynamic scan delay from exceeIf you are on a decent broadband or ethernet connection, I would recommend always using -T4. Some people love -T5 though it is too aggressive ding 10 ms for TCP ports and -T5 (insane) caps that value at 5 ms. If you are on a decent broadband or ethernet connection, I would recommend always using -T4. Some people love -T5 though it is too aggressive for my taste.

The -sn option means "no port scan":

This option tells Nmap not to do a port scan after host discovery, and only print out the available hosts that responded to the host discovery probes. This is often known as a “ping scan”, but you can also request that traceroute and NSE host scripts be run. This is by default one step more intrusive than the list scan, and can often be used for the same purposes. It allows light reconnaissance of a target network without attracting much attention. Knowing how many hosts are up is more valuable to attackers than the list provided by list scan of every single IP and host name.

Answer 2

The following (evil) code runs more than TWICE as fast as the nmap method

for i in {1..254} ;do (ping 192.168.1.$i -c 1 -w 5  >/dev/null && echo "192.168.1.$i" &) ;done

takes around 10 seconds, where the standard nmap

nmap -sP 192.168.1.1-254

takes 25 seconds...

Answer 3

Try this for a unique list.

ping -c 5 -b 10.10.0.255 | grep 'bytes from' | awk '{ print $4 }' | sort | uniq

another method (fetches live hosts):

fping -ag 192.168.1.0/24

Answer 4

Try both of these commands and see for yourself why arp is faster:

PING:

for ip in $(seq 1 254); do ping -c 1 10.185.0.$ip > /dev/null; [ $? -eq 0 ] && echo "10.185.0.$ip UP" || : ; done

ARP:

for ip in $(seq 1 254); do arp -n 10.185.0.$ip | grep Address; [ $? -eq 0 ] && echo "10.185.0.$ip UP" || : ; done

Answer 5

This is python code for the ping in range of the 192.168.0.0-192.168.0.100. You can change for loop as you comfort.

# -*- coding: utf-8 -*-
import socket
import os
import sys

up_ip =[] #list to store the ip-addresses of server online
for x in range(100):  #here range is 0-100. You can change the range according to your comfort

    server_ip = '192.168.0.'+ str(x)
    print "Trying ,server_ip,... \n"

    rep = os.system('ping -c 1 ' + server_ip)

    if rep == 0:
        up_ip.append(server_ip)
        print '******************* Server Is Up **************** \n'
    else:
        print 'server is down \n'

print up_ip

Answer 6

If time matters (and I know the feeling):

for i in {1..254}; do
echo -n -e "$i      \r"     
timeout --preserve-status .2  ping -c1 -q 10.0.0.$i  &> /dev/null
[ $? -eq 0 ]&&echo 10.0.0.$i is happy to serve to his master!
done # as I am

The command:

timeout --preserve-status .2  ping -c1 -q 10.0.0.107 &> /dev/null  ;echo $? 

returns 143 with non-existing PC and 0 with existing PC and waits for the answer just and only for .2 second because TIME MATTERS! And therefore I have to look for my lost keys now.

Answer 7

subnet="182.17.207"
fun(){
       ip="$subnet.$1"
       res=`ping -c 1 $ip | grep "1 packets transmitted, 1 received" | wc -l`
       if [ $res == 1 ]
       then
           echo "$ip => live"
       fi
}
for i in $(seq 1 254)
do
   fun $i &
   sleep 0.005
done
sleep 0.5
echo

Fast using linux fork, sleep is optional .. just to print in order.

Answer 8

This script runs on Git Bash (MINGW64) on Windows and return a messages depending of the ping result.

#!/bin/bash
#$1 should be something like "19.62.55"

if [ -z "$1" ]
  then
    echo "No identify of the network supplied, i.e. 19.62.55"
else
    ipAddress=$1

    for i in {1..256} ;do 
    (
        {
        ping -w 5 $ipAddress.$i ; 
        result=$(echo $?);
        } &> /dev/null


        if [ $result = 0 ]; then
            echo Successful Ping From : $ipAddress.$i
        else
            echo Failed Ping From : $ipAddress.$i
        fi &);
    done

fi

Answer 9

BSD's

for i in $(seq 1 254); do (ping -c1 -W5 192.168.1.$i >/dev/null && echo "192.168.1.$i" &) ;done

Answer 10

I really like the original reply but it did not give me the sequential sequence I was looking for.

I approached this a little different and it works great:

for ip in {int1..int2} 
do
    ping -c 1 xxx.xxx.xxx.$ip | grep "bytes from"
done