From owner-freebsd-net Thu Jun 22 11:12:25 2000 Delivered-To: freebsd-net@freebsd.org Received: from whale.sunbay.crimea.ua (whale.sunbay.crimea.ua [212.110.138.65]) by hub.freebsd.org (Postfix) with ESMTP id 0385F37BE9C for ; Thu, 22 Jun 2000 11:12:17 -0700 (PDT) (envelope-from ru@whale.sunbay.crimea.ua) Received: (from ru@localhost) by whale.sunbay.crimea.ua (8.9.3/1.13) id VAA32248; Thu, 22 Jun 2000 21:12:08 +0300 (EEST) Date: Thu, 22 Jun 2000 21:12:08 +0300 From: Ruslan Ermilov To: net@FreeBSD.org Subject: [CFV] where to put TCP MSS correction code Message-ID: <20000622211208.A30877@sunbay.com> Reply-To: Ruslan Ermilov Mail-Followup-To: net@FreeBSD.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi! There exists a well-known problem with broken Path MTU Discovery (see RFC 1191) due to the buggy router software and IP firewall misconfiguration. See http://www.FreeBSD.org/FAQ/ppp.html#AEN3714 and http://www.worldgate.com/~marcs/mtu/index.html for details. Patrick Bihan-Faou found a workaround for this problem where router "corrects" the value of TCP MSS option so that incoming packets are guaranteed to fit in advance without need to perform PMTU discovery cycle. If you are interested in this stuff, please choose from one of the following options, and reply directly to me at . 1. This functionality should be implemented within packet aliasing (NAT) library, libalias(3). This benefits from having this feature in both natd(8) and ppp(8). 2. This functionality is not suitable for NAT software and it should be implemented separately as a stand-alone daemon. (Already available at http://people.FreeBSD.org/~ru/tcpmssd.tgz). 3. Do both. Thank you, -- Ruslan Ermilov Oracle Developer/DBA, ru@sunbay.com Sunbay Software AG, ru@FreeBSD.org FreeBSD committer, +380.652.512.251 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message