From owner-freebsd-net  Thu Sep 26 10: 8:53 2002
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Date: Thu, 26 Sep 2002 10:07:41 -0700
From: Terry Lambert <tlambert2@mindspring.com>
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To: soheil h <soheil_h_y@hotmail.com>
Cc: freebsd-net@FreeBSD.ORG, freebsd-questions@FreeBSD.ORG
Subject: Re: UNKNOWN IP OPTION emergency
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soheil h wrote:
> as in stevens' Tcp/Ip illustrated says when a router see an unknown option
> it must silently ignore it but when i put an option by type 253 len 12 and
> 10 byte of data
> some router on my path drop it
> how can i set an option an put 2 ip address in it  that no router delete my
> data

Send a known option, instead?

Ignore := pass | drop

Normally, it means "drop", because unknown options are assumed to
be hop-to-hop, meaning it's illegal for them to come from a router
that did not originate them (i.e. a router that doesn't recognize
the option forwarding it to one that does).

If you want a covert data channel, you aren't going to be able to
do it with router options.  8-).

-- Terry

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