Find out who pings on a subnet quick and easy

  • Article

So i know there are tools out there to do this but figured some would be interested on how to do this real quick with stuff that's already in the OS.

1) Turn off echos to make the out put clean (don’t forget to turn it back on when its done via “echo on”).

2) The set is a sequence of numbers from start to end, by step amount.  So (1,1,5) would generate the sequence 1 2 3 4 5 and (5,-1,1) would generate the sequence (5 4 3 2 1).  So in this instance 1,1,254 would step to 254. 

3) For the ping the –n says send one request instead the default of four.  the –w sets the timeout for the echo request to 300 milliseconds, since I knew the subnet was close, so I did not need to wait the full timeout for the packet to return.

Example:

C:\debuggers>echo off
for /L %a in (1,1,254) do ping -n 1 -w 300 20.232.12.%a |findstr /i reply
Reply from 20.232.12.1: bytes=32 time=2ms TTL=245
Reply from 20.232.12.7: bytes=32 time=2ms TTL=55
Reply from 20.232.12.8: bytes=32 time=2ms TTL=53
Reply from 20.232.12.9: bytes=32 time=2ms TTL=55
Reply from 20.232.12.11: bytes=32 time=2ms TTL=53
Reply from 20.232.12.12: bytes=32 time=2ms TTL=55
Reply from 20.232.12.14: bytes=32 time=2ms TTL=55
Reply from 20.232.12.15: bytes=32 time=2ms TTL=53
Reply from 20.232.12.27: bytes=32 time=2ms TTL=53
Reply from 20.232.12.78: bytes=32 time=2ms TTL=53
Reply from 20.232.12.81: bytes=32 time=2ms TTL=55
Reply from 20.232.12.82: bytes=32 time=2ms TTL=53
Reply from 20.232.12.83: bytes=32 time=2ms TTL=53
Reply from 20.232.12.84: bytes=32 time=2ms TTL=53
Reply from 20.232.12.85: bytes=32 time=2ms TTL=55
Reply from 20.232.12.87: bytes=32 time=2ms TTL=53
Reply from 20.232.12.88: bytes=32 time=2ms TTL=53
Reply from 20.232.12.89: bytes=32 time=2ms TTL=53
Reply from 20.232.12.107: bytes=32 time=1ms TTL=53
Reply from 20.232.12.108: bytes=32 time=2ms TTL=53
Reply from 20.232.12.110: bytes=32 time=2ms TTL=53
Reply from 20.232.12.111: bytes=32 time=1ms TTL=55
Reply from 20.232.12.113: bytes=32 time=2ms TTL=55
Reply from 20.232.12.115: bytes=32 time=2ms TTL=55
Reply from 20.232.12.116: bytes=32 time=2ms TTL=53
Reply from 20.232.12.117: bytes=32 time=2ms TTL=55
Reply from 20.232.12.118: bytes=32 time=1ms TTL=55
Reply from 20.232.12.119: bytes=32 time=2ms TTL=53
Reply from 20.232.12.120: bytes=32 time=2ms TTL=53
Reply from 20.232.12.231: bytes=32 time=2ms TTL=53
Reply from 20.232.12.234: bytes=32 time=1ms TTL=55
Reply from 20.232.12.235: bytes=32 time=1ms TTL=55
Reply from 20.232.12.237: bytes=32 time=2ms TTL=55
Reply from 20.232.12.238: bytes=32 time=1ms TTL=55
Reply from 20.232.12.239: bytes=32 time=2ms TTL=53
Reply from 20.232.12.242: bytes=32 time=1ms TTL=55
Reply from 20.232.12.244: bytes=32 time=1ms TTL=55
Reply from 20.232.12.245: bytes=32 time=2ms TTL=53
Reply from 20.232.12.246: bytes=32 time=2ms TTL=53
Reply from 20.232.12.247: bytes=32 time=1ms TTL=55
Reply from 20.232.12.248: bytes=32 time=1ms TTL=55
Reply from 20.232.12.249: bytes=32 time=2ms TTL=53
Reply from 20.232.12.250: bytes=32 time=2ms TTL=55 

Update:

And in powershell:  1..254 | % {ping -n 1 -w 300 157.56.144.$_ | findstr /i reply }