From owner-freebsd-hackers  Tue Nov  7 10:07:46 1995
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.6.12/8.6.6) id KAA27795
          for hackers-outgoing; Tue, 7 Nov 1995 10:07:46 -0800
Received: from alpha.xerox.com (alpha.Xerox.COM [13.1.64.93])
          by freefall.freebsd.org (8.6.12/8.6.6) with SMTP id KAA27790
          for <hackers@freebsd.org>; Tue, 7 Nov 1995 10:07:44 -0800
Received: from crevenia.parc.xerox.com ([13.2.116.11]) by alpha.xerox.com with SMTP id <15936(4)>; Tue, 7 Nov 1995 10:03:34 PST
Received: from localhost ([127.0.0.1]) by crevenia.parc.xerox.com with SMTP id <177478>; Tue, 7 Nov 1995 10:03:23 -0800
X-Mailer: exmh version 1.6.4 10/10/95
To: guido@gvr.win.tue.nl (Guido van Rooij)
cc: jmb@kryten.atinc.com (Jonathan M. Bresler), hackers@freebsd.org
Subject: Re: [Q] Traceroute and source routing 
In-reply-to: Your message of "Mon, 06 Nov 1995 11:14:55 PST."
             <199511061914.UAA24264@gvr.win.tue.nl> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Tue, 7 Nov 1995 10:03:12 PST
From: Bill Fenner <fenner@parc.xerox.com>
Message-Id: <95Nov7.100323pst.177478@crevenia.parc.xerox.com>
Sender: owner-hackers@freebsd.org
Precedence: bulk

In message <199511061914.UAA24264@gvr.win.tue.nl> you write:
>traceroute
>sets the source route correctly using the IP_OPTIONS socket option and
>then sets the IP_HDRINCL socket option to allow it to pass a complete IP
>header (with its desired value of the TTL).  But newer systems do not
>insert the IP options specified by IP_OPTIONS if IP_HDRINCL is also set
>(for a SOCK_RAW Internet socket), meaning the source route option is never
>used by the kernel!

I talked to Rich Stevens about this a while back, and he agreed that it's 
bogus and that IP_OPTIONS should not be ignored if you set IP_HDRINCL, but 
Garrett pushed back on the idea and I didn't feel like pushing forward...

  Bill