ping 172.17.11220...Please explain why its pinging without decimal

Unanswered Question
Jun 3rd, 2008
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Dear frdz..

please explain why i am getting reply from below ip address even have not put decimal betn last two digits...

C:\ping 172.17.11220

Pinging with 32 bytes of data:

Reply from bytes=32 time=110ms TTL=125

Reply from bytes=32 time=115ms TTL=125

Reply from bytes=32 time=47ms TTL=125

Reply from bytes=32 time=111ms TTL=125

Ping statistics for

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 47ms, Maximum = 115ms, Average = 95ms

Thanks in advance

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Overall Rating: 4.6 (5 ratings)
hassaan_st Tue, 06/03/2008 - 21:48
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Dear fellow,

It worked in the following way.

The portion without decimal is '11220'.The system first converted '11220' into binary form '10101111010100'. Then it further broke this binary combination into two parts, starting from right hand side and collecting maximum 8 possible bits.

Which means,starting from the right hand side,it collected 8 bits,i.e. '11010100', and converted it into decimal form, i.e. '212'.

Then coming to the second part of binary numbers i.e. '101011', and converted it into decimal form, i.e. '43'.

In this way, it translated '11220' into '43.212'.

This is my understanding, waiting for some expert to confirm...

Hope it helps



cindylee27 Thu, 06/05/2008 - 23:53
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wow..something interesting ! that i never known off.. must try ! :)

Kevin Dorrell Fri, 06/06/2008 - 01:18
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Fascinating! I never knew that!

It works on a PC, and it works on Solaris. Not on a router though; that still gives "% Unrecognised host or address, or protocol not running."

I wondered whether there was some classful behavior here, but apparently not. ping 192.168.4865 really does ping Even ping 3232240385 actually pings !

Kevin Dorrell


mohammedmahmoud Fri, 06/06/2008 - 04:49
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Hi All,

Nice post Hassan, to add a little bit you can also write it in hexa (but make sure that the number is preceded by 0x). Microsoft Windows TCP/IP applications such as ping, ftp and telnet accepts IP addresses in many forms, using the inet_addr() sockets function it translates IP addresses into the final 4-byte addresses. This function accepts an IP address in decimal, octal, or hexadecimal form.


Mohammed Mahmoud.


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