From owner-freebsd-net@FreeBSD.ORG Tue Jan 18 17:59:00 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 42C5710656A3 for ; Tue, 18 Jan 2011 17:59:00 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout025.mac.com (asmtpout025.mac.com [17.148.16.100]) by mx1.freebsd.org (Postfix) with ESMTP id 27ECB8FC2A for ; Tue, 18 Jan 2011 17:58:59 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from [17.153.49.243] by asmtp025.mac.com (Oracle Communications Messaging Exchange Server 7u4-20.01 64bit (built Nov 21 2010)) with ESMTPSA id <0LF800AB0CMAS600@asmtp025.mac.com> for freebsd-net@freebsd.org; Tue, 18 Jan 2011 09:58:59 -0800 (PST) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.2.15,1.0.148,0.0.0000 definitions=2011-01-18_06:2011-01-18, 2011-01-18, 1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1010190000 definitions=main-1101180121 From: Chuck Swiger In-reply-to: <60CA2B35-71FF-4A7A-9C46-22B3F8C106D2@Chaos1.DE> Date: Tue, 18 Jan 2011 09:58:57 -0800 Message-id: <0358F6C5-BCCD-4289-8522-B2945EDEC315@mac.com> References: <71EEB2EA-3F48-4850-AB9C-92E47ED72D99@Chaos1.DE> <4D359841.50306@aws-net.org.ua> <60CA2B35-71FF-4A7A-9C46-22B3F8C106D2@Chaos1.DE> To: Axel Rau X-Mailer: Apple Mail (2.1082) Cc: freebsd-net@freebsd.org Subject: Re: RESOLVED: Re: 8.1 Box does not react on ICMP "unreachable - need to frag" 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, 18 Jan 2011 17:59:00 -0000 On Jan 18, 2011, at 6:14 AM, Axel Rau wrote: > Am 18.01.2011 um 14:40 schrieb Artyom Viklenko: >> Make sure DB2 got ICMP need-frag message and it not blocked. >> Also, check sysctl variable 'net.inet.tcp.path_mtu_discovery'. > > Yes to both. So this is a bug in 8.1? If DF is true and the packet exceeds the MTU, then it is dropped per RFC-791. This can be used by pMTU discovery, if enabled. Regards, -- -Chuck