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Date:	Thu, 30 Mar 2017 19:38:42 +0300
From:	Andrey Repin <anrdaemon AT yandex DOT ru>
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To:	=?utf-8?B?6auY6ZSL?= <gao_feng AT 139 DOT com>, cygwin AT cygwin DOT com
Subject:	Re: reply: problem with nc 1.107-4
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Greetings, 高锋!

Please don' top-post. Thank you.

> Two days ago,i wanted to determine whether a udp port of another machine is
> open or not, which is deployed on different subnet.
> But windows platform does not provide utility that can dose this.So i
> downloaded a setup.exe from cygwin,of which version is 2.877(64 bit),and i had never use this utility before.

UDP protocol is inherently stateless.
You can't determine remote port state unless it explicitly reported (i.e.
answers to the messages sent on that port).


-- 
With best regards,
Andrey Repin
Thursday, March 30, 2017 19:36:15

Sorry for my terrible english...
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