From owner-freebsd-net@FreeBSD.ORG Tue Jun 27 18:55:48 2006 Return-Path: X-Original-To: net@freebsd.org Delivered-To: freebsd-net@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E216016A407 for ; Tue, 27 Jun 2006 18:55:48 +0000 (UTC) (envelope-from mi+mx@aldan.algebra.com) Received: from aldan.algebra.com (aldan.algebra.com [216.254.65.224]) by mx1.FreeBSD.org (Postfix) with ESMTP id 52A3843DDE for ; Tue, 27 Jun 2006 18:55:47 +0000 (GMT) (envelope-from mi+mx@aldan.algebra.com) Received: from corbulon.video-collage.com (static-151-204-231-237.bos.east.verizon.net [151.204.231.237]) by aldan.algebra.com (8.13.6/8.13.6) with ESMTP id k5RIthgA094940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 27 Jun 2006 14:55:46 -0400 (EDT) (envelope-from mi+mx@aldan.algebra.com) Received: from [172.21.130.86] (mx-broadway [38.98.68.18]) by corbulon.video-collage.com (8.13.6/8.13.6) with ESMTP id k5RItbXs084819 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 27 Jun 2006 14:55:38 -0400 (EDT) (envelope-from mi+mx@aldan.algebra.com) From: Mikhail Teterin Organization: Virtual Estates, Inc. To: net@freebsd.org Date: Tue, 27 Jun 2006 14:55:32 -0400 User-Agent: KMail/1.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606271455.32276.mi+mx@aldan.algebra.com> X-Virus-Scanned: ClamAV 0.88/1564/Mon Jun 26 10:55:16 2006 on corbulon.video-collage.com X-Virus-Status: Clean X-Scanned-By: MIMEDefang 2.43 Cc: Subject: fetch http://localhost:6666 hangs X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Jun 2006 18:55:49 -0000 Hello! I just noticed, that on my recent "6.1-STABLE #4: Thu Jun 8" amd64 system attempts to connect to a bogus port (like 6666) hang instead of failing with "Connection refused" immediately, as they on other systems. Why would this be? There is nothing listening: ``netstat -n | grep 6666'' is empty. The ipfw rules are very simple: 00200 pipe 1 ip from any to 172.21.128.43 dst-port 2049 65535 allow ip from any to any While fetch is trying to connect, the tcpdump prints: % tcpdump -vvv -i lo0 port 6666 tcpdump: listening on lo0, link-type NULL (BSD loopback), capture size 68 bytes 14:28:43.465182 IP (tos 0x0, ttl 64, id 56427, offset 0, flags [DF], proto: TCP (6), length: 64) localhost.52326 > localhost.6666: S, cksum 0x0558 (correct), 583002422:583002422(0) win 65535 14:28:46.464121 IP (tos 0x0, ttl 64, id 56491, offset 0, flags [DF], proto: TCP (6), length: 64) localhost.52326 > localhost.6666: S, cksum 0xf99f (correct), 583002422:583002422(0) win 65535 14:28:49.663980 IP (tos 0x0, ttl 64, id 56530, offset 0, flags [DF], proto: TCP (6), length: 64) localhost.52326 > localhost.6666: S, cksum 0xed1f (correct), 583002422:583002422(0) win 65535 14:28:52.863836 IP (tos 0x0, ttl 64, id 56559, offset 0, flags [DF], proto: TCP (6), length: 48) localhost.52326 > localhost.6666: S, cksum 0x5993 (correct), 583002422:583002422(0) win 65535 [...] Meanwhile, a "healthy" system prints: % tcpdump -vvv -i lo0 port 6666 tcpdump: listening on lo0, link-type NULL (BSD loopback), capture size 68 bytes 14:29:55.716350 IP (tos 0x0, ttl 64, id 7958, offset 0, flags [DF], proto: TCP (6), length: 64) localhost.49238 > localhost.6666: S, cksum 0x7d0e (correct), 3929347125:3929347125(0) win 65535 14:29:55.718358 IP (tos 0x0, ttl 64, id 7959, offset 0, flags [DF], proto: TCP (6), length: 40) localhost.6666 > localhost.49238: R, cksum 0xd901 (correct), 0:0(0) ack 3929347126 win 0 Any clues? Thanks! -mi