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Hello. Maybe this can appear in http://ss64.com/nt/ping.html
I get this info time ago, and can be useful.
The default values for ping are:
-l 32
-w 4000
Currently. it says "default time period of one second." but are 4 seconds.
And a update or improve for the sleep trick using ping. Current it uses PING -n 31 127.0.0.1>nul but it not very exact. For example: -n 2 can consume 1 second.
For get the sleep trick using the ping, we need specify the timeout request in milliseconds using the option -w.
For consume the timeout we need specify a ip that will not response. Other than 127.0.0.1 (because this always response, even without any network card ).
What ip can use?
In windows xp the first valid ip is 0.0.0.0, but on windows 8 it is not considered valid (message: "PING: transmit failed. General failure."). Windows 8 accept as first valid ip: 1.0.0.0 (message: "Request timed out."). Using the ip 1.0.0.0 we ensure that ip will not response, and ping will wait the timeout.
Then, for compatibility with windows xp and windows 8, we can get the sleep effect using ping using this:
for 3 seconds (3*1000) = 3000 milliseconds
ping -l 0 -n 1 -w 3000 1.0.0.0 >nul
That means echo 1 request ping to server 1.0.0.0 with a buffer of size 0 and use a timeout of 3000 milliseconds (3 seconds).
Last edited by carlos (01 May 2014 08:16)
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"1.0.0.0/8 has been assigned by IANA to APNIC on the 19th January 2010, for use for as public unicast space for further address allocations and assignments."
see
http://www.potaroo.net/studies/1slash8/1slash8.html
So I'm not sure that it's safe to use IP addresses other than the loopback address, even if you find an address that seems fine now it could change in a few years.
Anyway, I have updated the page with a few changes including the correct defaults, thanks for the info.
The 1 second thing is not a timeout but the delay between pings, this is why 3 pings gives a delay of 2 seconds.
Simon
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Thanks Simon.
Is interesting for me read about that IP range.
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Hi,
Regard the sleep use of ping, I thinks that the only IP's that is not preposed for Wan or Lan are the Ip's of special uses. The Ip for the TEST-NET* not are used in Wan or Lan and might be an option.
The blocks 192.0.2.0/24 (TEST-NET-1), 198.51.100.0/24 (TEST-NET-2),
and 203.0.113.0/24 (TEST-NET-3) are provided for use in
documentation.
I use for example the classical 192.0.2.0 for Ping -w how sleep/delay/wait
Ref: rfc5737
einstein1969
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good info einstein1969. Thanks.
But i think that is better 203.0.113.0 because looks like a public ip but not used as public ip.
But, for avoid suspect of ping to public ip, the ip that you use ( 192.0.2.0 ) looks better.
Then, the sleep effect can be considered safe using:
ping -l 0 -n 1 -w 3000 192.0.2.0 >nul
Last edited by carlos (02 May 2014 21:02)
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If the variable:
SystemRoot=C:\Windows
is not defined , the ping report incomplete/dirty information:
>ping 127.0.0.1 -n 3
Esecuzione di Ping con 32 byte di dati:
Risposta da 127.0.0.1: byte=32 durata<1ms TTL=128
Risposta da 127.0.0.1: byte=32 durata<1ms TTL=128
Risposta da 127.0.0.1: byte=32 durata<1ms TTL=128
Statistiche Ping per uö,¯þÿÿÿ(õ%:
Pacchetti: Trasmessi = 3, Ricevuti = 3,
Persi = 0 (0% persi),
Tempo approssimativo percorsi andata/ritorno in millisecondi:
Minimo = 0ms, Massimo = 0ms, Medio = 0ms
on Windows 7 32bit
einstein1969
Last edited by einstein1969 (10 May 2014 23:26)
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^ Thats a strange bug, running repeated pings, the corrupted text is (usually) different for each run:
Instead of "Ping statistics for 127.0.0.1"
Ping statistics for °z↓:
Ping statistics for °-9:
Ping statistics for h0:
Attempting to ping a remote machine or website fails completely if %systemroot% is undefined
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Hi,
Regard the sleep use of ping, I thinks that the only IP's that is not preposed for Wan or Lan are the Ip's of special uses. The Ip for the TEST-NET* not are used in Wan or Lan and might be an option.
The blocks 192.0.2.0einstein1969
The problem I see with this is that the behaviour of a test net IP address is undefined, it is allocated "for use in documentation and example code." using PING to generate a delay may be unconventional but it is still a valid use of the network, so I think the most appropriate address to use is the loopback adapter.
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