Pinging 192.0.2.2 Receives a Response...but shouldn't

Question

I'm using the windows batch script function ping 192.0.2.2 -n 1 -w 10000 > nul on my local machine (Windows 7) in a command prompt to test its functionality. The explanation of the function is here: "How to wait in a batch script?".

I've used 192.0.2.2 because it is considered a reserved IP address, so there should be no response. But instead, my results are inconsistent - sometimes I get a response with the error "Destination net unreachable."

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Reply from 10.10.251.2: Destination net unreachable.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Request timed out.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Request timed out.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Request timed out.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Reply from 10.10.251.2: Destination net unreachable.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),

C:\Users\MrF>ping 192.0.2.2 -n 1 -w 10000

Pinging 192.0.2.2 with 32 bytes of data:
Request timed out.

Ping statistics for 192.0.2.2:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\MrF>

Unfortunately, the function only waits 10 seconds when the ping is lost. Pings that receive a response don't wait at all. This has lead to some frustrating lack of functionality in my scripts that require wait commands. How can I fix this? Why is it happening?

Answer 1

That is not a link local or LAN reserved IP range, but it is routable (although no one should ever route to it). See this whois info for full details. A link local 169.254 range IP would give more consistent, reliable results. See this answer for further explanation.

Edit: I see what you mean. Even my previous 169.254 solution is subject to the same inconsistency. Well, really, the biggest benefit to pinging a bogus IP with the -w switch is so you can pause in milliseconds. If you're pausing in whole seconds (such as ten seconds in your example above), just

ping -n 11 localhost >NUL

... where 11 is N+1 seconds to pause. That command will pause for 10 seconds.

Alternatively, you could use the timeout /t 10 /NOBREAK >NUL command if your script will be run on Vista or newer.

If you need fraction-of-a-second pausing, you could always employ VBScript or JScript.

@if (@CodeSection == @Batch) @then

@echo off
setlocal

set /P "=Pausing 1.5 seconds."<NUL
call :sleep 500
set /P "=."<NUL
call :sleep 500
set /P "=. "<NUL
call :sleep 500
echo Done.

goto :EOF

:sleep <milliseconds>
cscript /nologo /e:JScript "%~f0" "%~1"
goto :EOF

@end // end Batch / begin JScript
WSH.Sleep(WSH.Arguments(0) * 1);

Answer 2

Windows has many wait commands, I use waitfor. But there is choice and timeout as well.

Maybe stop searching the internet. Ping is a silly idea. What would happen if all 175,000 computers at my work all started pinging at the same time.

waitfor /t 99999 Fred