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From: "Ronald F. Guilmette" <rfg@tristatelogic.com>
To: freebsd-net@freebsd.org, Jamie Landeg-Jones <jamie@catflap.org>
Subject: Re: Same host or different? How can you tell "over the wire"?
In-Reply-To: <201803241747.w2OHlupR069759@donotpassgo.dyslexicfish.net>
Date: Sat, 24 Mar 2018 11:38:05 -0700
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In message <201803241747.w2OHlupR069759@donotpassgo.dyslexicfish.net>, 
Jamie Landeg-Jones <jamie@catflap.org> wrote:

>Have you thought of examining the TCP timestamp field? Not necessarily
>for accurate uptime, but a way to determine if the hosts are the same.

No, I certainly didn't, but that appears to be the exact kind of thing
I was looking for, so thanks!  (I will have to look into it some more.
I have just skimmed RFC 1323 for the very first time ever, and it will
take me awhile to fully grok this stuff.)

>Or some of the other fingerprinting methods? nmap has options for uptime
>and other fingerprinting : https://nmap.org/book/osdetect-usage.html

I'm not seeing a separate option just for the uptime, apart from the
full blown OS detection.  Did I just miss it?