From owner-freebsd-bugs Fri Sep 6 10:50: 9 2002 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3577337B400 for ; Fri, 6 Sep 2002 10:50:04 -0700 (PDT) Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id E39BF43E3B for ; Fri, 6 Sep 2002 10:50:03 -0700 (PDT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.4/8.12.4) with ESMTP id g86Ho3JU096655 for ; Fri, 6 Sep 2002 10:50:03 -0700 (PDT) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.4/8.12.4/Submit) id g86Ho3tw096653; Fri, 6 Sep 2002 10:50:03 -0700 (PDT) Date: Fri, 6 Sep 2002 10:50:03 -0700 (PDT) Message-Id: <200209061750.g86Ho3tw096653@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: Martin Kaeske Subject: Re: kern/42137: Path MTU broken - initial too-large packet continuously resent Reply-To: Martin Kaeske Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org The following reply was made to PR kern/42137; it has been noted by GNATS. From: Martin Kaeske To: Jeff Behl Cc: freebsd-gnats-submit@FreeBSD.org Subject: Re: kern/42137: Path MTU broken - initial too-large packet continuously resent Date: Fri, 6 Sep 2002 19:46:00 +0200 Hi Jeff, Thanks for the tcpdump, i think i was able to identify the problem. As i wrote in the PR tcp_ctlinput() is responsible for calling tcp_mtudisc but tcp_ctlinput() does not only check src/dst-port it also examines wether the tcp-sequence number (found in the ICMP-response) is between snd_una (send unacknowledged) and snd_max (highest number sent). I found out that the ICMP-responses doesn't contain the correct seq. number, the first two bytes are correct but the last two aren't. So i think it is a router problem (as it was in my case ;). HTH Martin -- "At the beginning of the week, we sealed ten BSD programmers into a computer room with a single distribution of BSD Unix. Upon opening the room after seven days, we found all ten programmers dead, clutching each others throats, and thirteen new flavors of BSD." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message