From owner-freebsd-questions Wed Oct 21 06:34:14 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA17384 for freebsd-questions-outgoing; Wed, 21 Oct 1998 06:34:14 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from pp3.shef.ac.uk (pp3.shef.ac.uk [143.167.2.3]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id GAA17362 for ; Wed, 21 Oct 1998 06:34:10 -0700 (PDT) (envelope-from nick@dcs.shef.ac.uk) Received: from [143.167.11.165] (helo=dcs.shef.ac.uk ident=root) by pp3.shef.ac.uk with esmtp (Exim 2.02 #2) id 0zVyOS-0007eS-00 for freebsd-questions@FreeBSD.ORG; Wed, 21 Oct 1998 14:33:41 +0100 Message-ID: <362DE373.4A79CFC2@dcs.shef.ac.uk> Date: Wed, 21 Oct 1998 14:36:51 +0100 From: "Nick A. Fikouras" X-Mailer: Mozilla 4.05 [en] (X11; I; Linux 2.0.24 i686) MIME-Version: 1.0 To: "freebsd-questions@FreeBSD.ORG" Subject: 40 octet IP header? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In several tcp connections performed between two freebsd-2.2.2 machines connected with an Ethernet link (mtu 1500 octets), I observed with tcpdump that the data field takes up only 1440 octets of the whole IP packet. Assuming that the tcp header is 20 octets long, this leaves us with a 40 octet IP header. Obviously, by default the system requires some options in the IP header (i.e. timestamp). How can I configure this default options, even turn them off? thank you in advance, --nick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message