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Date:      Sat, 14 Dec 2002 10:25:30 +0100
From:      Brad Knowles <brad.knowles@skynet.be>
To:        "Jimi Thompson" <jimit@myrealbox.com>
Cc:        <current@freebsd.org>
Subject:   Re: TTL
Message-ID:  <a05200f00ba20a8a20b27@[10.0.1.3]>
In-Reply-To: <JBEBLBLAABEOPMEPFAKEIEHKCCAA.jimit@myrealbox.com>
References:  <JBEBLBLAABEOPMEPFAKEIEHKCCAA.jimit@myrealbox.com>

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At 9:14 PM -0800 2002/12/13, Jimi Thompson wrote:

>  With the increasing complexity of the internet, this is often a problem for
>  those who have large internal networks and/or live in Australia.  30 hops
>  often isn't enough to make to the core DNS.  It probably ought to be
>  extended to something more realistic.  The other numbers that I've seen used
>  64, 128, and 256.

	We ran into this problem in '96, when I was working at AOL.  We 
had a guy in California who wanted to send e-mail to his friend 
across the hall, but of course those packets had to traverse the 
country to be delivered to our servers in Virginia.  We went back and 
forth a few times, and I even set up tcpdump on the particular 
machine I told him to connect directly to -- I could see his packets 
coming in, but our responses were never received.

	Turns out that, by a quirk of routing fate, he was something like 
32 hops away, and while his OS was fine, our particular patch 
revision of HP-UX 9 was hard-coded at 30.  We applied a later patch 
to the machines, and everything went back to normal.


	This is not a new problem.  Unfortunately, many OSes may still 
have inappropriate values defined.

-- 
Brad Knowles, <brad.knowles@skynet.be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
     -Benjamin Franklin, Historical Review of Pennsylvania.

GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
!w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)

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