From owner-freebsd-hackers Mon Dec 7 06:51:14 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA04440 for freebsd-hackers-outgoing; Mon, 7 Dec 1998 06:51:14 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from relay.ucb.crimea.ua (relay.ucb.crimea.ua [194.93.177.113]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id GAA04152 for ; Mon, 7 Dec 1998 06:48:09 -0800 (PST) (envelope-from ru@ucb.crimea.ua) Received: (from ru@localhost) by relay.ucb.crimea.ua (8.8.8/8.8.8) id QAA13393; Mon, 7 Dec 1998 16:36:07 +0200 (EET) (envelope-from ru) Date: Mon, 7 Dec 1998 16:36:06 +0200 From: Ruslan Ermilov To: Thomas David Rivers Cc: marcs@znep.com, nate@mt.sri.com, dillon@apollo.backplane.com, eischen@vigrid.com, hackers@FreeBSD.ORG, luigi@labinfo.iet.unipi.it Subject: Re: TCP bug Message-ID: <19981207163606.A7575@ucb.crimea.ua> Mail-Followup-To: Thomas David Rivers , marcs@znep.com, nate@mt.sri.com, dillon@apollo.backplane.com, eischen@vigrid.com, hackers@FreeBSD.ORG, luigi@labinfo.iet.unipi.it References: <199812071401.JAA26369@lakes.dignus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.94.17i In-Reply-To: <199812071401.JAA26369@lakes.dignus.com>; from Thomas David Rivers on Mon, Dec 07, 1998 at 09:01:45AM -0500 X-Operating-System: FreeBSD 2.2.7-STABLE i386 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, Dec 07, 1998 at 09:01:45AM -0500, Thomas David Rivers wrote: > Ok - > > As I understood this discussion (which seemed clear to me); the > problem was that an internal node (behind the firewall) couldn't > get to some web sites because of fragmentation issues. The low > MTU at the firewall/gateway broke path MTU discovery.. No, the problem is not with low MTU, but because AOL is blocking ICMP: PING aol.com (152.163.210.29): 56 data bytes 36 bytes from www2-r10-P5-0-0.tpopr-rri.aol.com (152.163.133.6): Communication prohibited by filter Vr HL TOS Len ID Flg off TTL Pro cks Src Dst 4 5 00 5400 68cb 0 0000 ea 01 894d 194.93.177.113 152.163.210.29 ^C --- aol.com ping statistics --- 22 packets transmitted, 0 packets received, 100% packet loss > > So - a possible work-around to the problem should be to set the > SL/IP MTU at 1500 at the gateway - right? Does your router run FreeBSD? If yes, how did you change MTU on SLIP? -- Ruslan Ermilov Sysadmin and DBA of the ru@ucb.crimea.ua United Commercial Bank +380.652.247.647 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message