From owner-freebsd-hackers Sat Jan 5 10:40:41 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from freesbee.wheel.dk (freesbee.wheel.dk [193.162.159.97]) by hub.freebsd.org (Postfix) with ESMTP id BB9DF37B41D for ; Sat, 5 Jan 2002 10:40:38 -0800 (PST) Received: by freesbee.wheel.dk (Postfix, from userid 1001) id 0A3995DD0; Sat, 5 Jan 2002 19:40:38 +0100 (CET) Date: Sat, 5 Jan 2002 19:40:38 +0100 From: Jesper Skriver To: "Louis A. Mamakos" Cc: Guido van Rooij , Terry Lambert , William Carrel , freebsd-hackers@FreeBSD.ORG Subject: Re: path_mtu_discovery Message-ID: <20020105194037.G28939@FreeBSD.org> Mail-Followup-To: Jesper Skriver , "Louis A. Mamakos" , Guido van Rooij , Terry Lambert , William Carrel , freebsd-hackers@FreeBSD.ORG References: <26E71536-013D-11D6-8ED3-003065D5E9A4@infospace.com> <3C36149B.B9C02DCF@mindspring.com> <20020104223235.GA64301@gvr.gvr.org> <200201042302.g04N2A789953@whizzo.transsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200201042302.g04N2A789953@whizzo.transsys.com>; from louie@TransSys.COM on Fri, Jan 04, 2002 at 06:02:10PM -0500 X-PGP-Fingerprint: 6B88 9CE8 66E9 E631 C9C5 5EB4 22AB F0EC F956 1C31 X-PGP-Public-Key: http://freesbee.wheel.dk/~jesper/gpgkey.pub Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, Jan 04, 2002 at 06:02:10PM -0500, Louis A. Mamakos wrote: > > One possibility is that the code in icmp_input() processing the > PMTU discovery-induced ICMP message could verify that the returned > header in fact is associated with a connection on the host and > maybe even has sane sequence numbers (for TCP segments). The code does that today src/sys/netinet/tcp_subr.c in tcp_ctlinput() added in rev 1.94 on february 26th 2001 when it was moved from src/sys/netinet/in_pcb.c in_pcbnotify() added in rev 1.70 on december 24th 2000 > This would make it more difficult to just spray these packets at host > and drop the MTU on routes. /Jesper -- Jesper Skriver, jesper(at)skriver(dot)dk - CCIE #5456 Work: Network manager @ AS3292 (Tele Danmark DataNetworks) Private: FreeBSD committer @ AS2109 (A much smaller network ;-) One Unix to rule them all, One Resolver to find them, One IP to bring them all and in the zone to bind them. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message