From owner-freebsd-net Tue Jun 20 17:22:51 2000 Delivered-To: freebsd-net@freebsd.org Received: from whizzo.transsys.com (whizzo.TransSys.COM [144.202.42.10]) by hub.freebsd.org (Postfix) with ESMTP id 5E10537B904 for ; Tue, 20 Jun 2000 17:22:48 -0700 (PDT) (envelope-from louie@whizzo.transsys.com) Received: from whizzo.transsys.com (localhost.transsys.com [127.0.0.1]) by whizzo.transsys.com (8.9.3/8.9.1) with ESMTP id UAA27742; Tue, 20 Jun 2000 20:22:44 -0400 (EDT) (envelope-from louie@whizzo.transsys.com) Message-Id: <200006210022.UAA27742@whizzo.transsys.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Julie Elizabeth Schlembach Cc: Garrett Wollman , freebsd-net@FreeBSD.ORG X-Image-URL: http://www.transsys.com/louie/images/louie-mail.jpg From: "Louis A. Mamakos" Subject: Re: Using timestamp option of ip header (IPOPT_TS) References: In-reply-to: Your message of "Tue, 20 Jun 2000 13:23:46 CDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 20 Jun 2000 20:22:44 -0400 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > > by reading and writing the option explicitly > > (IP_RECVOPTS and IP_OPTIONS). > > Thanks for your input so far. This seems to be what we would like to do - > how exactly do we go about doing it? What part of the code needs to be > modified? We are using FreeBSD v3.2. > You should really think twice about using this mechanism in any sort of application that you care about. Most routers which are used on the global Internet are optimized for forwarding "normal" traffic at very high rates of speed and completely insane packet-per-second forwarding rate. Processing the record route with timestamp IP option (and source route) will cause the packet to generally not be forwarded along the highly optimized (and in most cases, hardware assisted) path, but to be faulted up to a CPU to be processed as an exception in a the "slow" path. There are other mechanisms available to capture a timestamp of when the packet was received on the local FreeBSD box if that's the timestamp you're concerned with. louie To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message