From owner-freebsd-hackers Wed Oct 8 23:20:58 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA11743 for hackers-outgoing; Wed, 8 Oct 1997 23:20:58 -0700 (PDT) (envelope-from owner-freebsd-hackers) Received: from sax.sax.de (sax.sax.de [193.175.26.33]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id XAA11737 for ; Wed, 8 Oct 1997 23:20:54 -0700 (PDT) (envelope-from j@uriah.heep.sax.de) Received: (from uucp@localhost) by sax.sax.de (8.6.12/8.6.12-s1) with UUCP id IAA09463 for hackers@FreeBSD.ORG; Thu, 9 Oct 1997 08:20:45 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.8.7/8.8.5) id IAA18642; Thu, 9 Oct 1997 08:17:48 +0200 (MET DST) Message-ID: <19971009081748.NT15455@uriah.heep.sax.de> Date: Thu, 9 Oct 1997 08:17:48 +0200 From: j@uriah.heep.sax.de (J Wunsch) To: hackers@FreeBSD.ORG Subject: Re: TCP problem References: <19971008124102.17436@lemis.com> <199710082153.TAA24952@gaia.coppe.ufrj.br> X-Mailer: Mutt 0.60_p2-3,5,8-9 Mime-Version: 1.0 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: <199710082153.TAA24952@gaia.coppe.ufrj.br>; from Joao Carlos Mendes Luis on Oct 8, 1997 19:53:08 -0200 Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk As Joao Carlos Mendes Luis wrote: > ... Also, > FreeBSD is sending these packets as "Don't Fragment", is this a "feature" ? I think so. It's called ``path MTU discovery'', and means the sending site attempts to lower the sent packet size enough so there's nevery any need for an intermediate router to fragment it. By setting DF, any router that would fragment it will throw it away, and return an ``ICMP fragmentation needed'' instead. (At least, that's the way i understand path MTU discovery.) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)