From owner-freebsd-net@FreeBSD.ORG Tue Feb 13 18:19:00 2007 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D715016A402 for ; Tue, 13 Feb 2007 18:19:00 +0000 (UTC) (envelope-from Stephen.Clark@seclark.us) Received: from smtpout05-04.prod.mesa1.secureserver.net (smtpout05-04.prod.mesa1.secureserver.net [64.202.165.221]) by mx1.freebsd.org (Postfix) with SMTP id BFB6E13C442 for ; Tue, 13 Feb 2007 18:19:00 +0000 (UTC) (envelope-from Stephen.Clark@seclark.us) Received: (qmail 9275 invoked from network); 13 Feb 2007 18:19:00 -0000 Received: from unknown (24.144.77.243) by smtpout05-04.prod.mesa1.secureserver.net (64.202.165.221) with ESMTP; 13 Feb 2007 18:19:00 -0000 Message-ID: <45D20113.1060403@seclark.us> Date: Tue, 13 Feb 2007 13:18:59 -0500 From: Stephen Clark User-Agent: Mozilla/5.0 (X11; U; Linux 2.2.16-22smp i686; en-US; m18) Gecko/20010110 Netscape6/6.5 X-Accept-Language: en-us, en MIME-Version: 1.0 To: dart@es.net References: <45D1E669.30402@seclark.us> <45D1F216.1090708@es.net> In-Reply-To: <45D1F216.1090708@es.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: pmtud problem X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Stephen.Clark@seclark.us List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Feb 2007 18:19:00 -0000 Eli Dart wrote: >-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > > > >Stephen Clark wrote: > > > >>if the pc sends a packet of 1460 bytes with the DF bit set shouldn't the >>freebsd 4.9 system >>send back an icmp dest unreachable - fragmentation needed and DF bit set? >> >> > >Are you blocking icmp with a firewall filter? > > --eli > > > Good question - but the answer is no. The other interesting fact is when I drop the mtu on the gre to 1412 I do see the icmp messages. >>$ sysctl -a | grep mtu >>net.inet.tcp.path_mtu_discovery: 1 >> >>Now if I change the mtu of the gre to 1412 everything works. >> >>Any insight would be appreciated. >> >>Thanks, >>Steve >> >> > >- -- >Eli Dart Office: (510) 486-5629 >ESnet Network Engineering Group Fax: (510) 486-6712 >Lawrence Berkeley National Laboratory >PGP Key fingerprint = C970 F8D3 CFDD 8FFF 5486 343A 2D31 4478 5F82 B2B3 >-----BEGIN PGP SIGNATURE----- >Version: GnuPG v1.4.6 (FreeBSD) > >iD4DBQFF0fIWLTFEeF+CsrMRAig5AKDLp0PzYvaH93VZSfkiTMWorKCkBwCY6a78 >qWtMMH4GdqHFac6frQjb7w== >=06S0 >-----END PGP SIGNATURE----- >_______________________________________________ >freebsd-net@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-net >To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > > > -- "They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." (Ben Franklin) "The course of history shows that as a government grows, liberty decreases." (Thomas Jefferson)