From owner-freebsd-hackers Wed Dec 2 09:10:32 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA13768 for freebsd-hackers-outgoing; Wed, 2 Dec 1998 09:10:32 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from ns.mt.sri.com (sri-gw.MT.net [206.127.105.141]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA13754 for ; Wed, 2 Dec 1998 09:10:29 -0800 (PST) (envelope-from nate@mt.sri.com) Received: from mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by ns.mt.sri.com (8.8.8/8.8.8) with SMTP id KAA08487; Wed, 2 Dec 1998 10:10:04 -0700 (MST) (envelope-from nate@rocky.mt.sri.com) Received: by mt.sri.com (SMI-8.6/SMI-SVR4) id KAA06313; Wed, 2 Dec 1998 10:09:47 -0700 Date: Wed, 2 Dec 1998 10:09:47 -0700 Message-Id: <199812021709.KAA06313@mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Thomas David Rivers Cc: eischen@vigrid.com, nate@mt.sri.com, dillon@apollo.backplane.com, hackers@FreeBSD.ORG, luigi@labinfo.iet.unipi.it Subject: Re: TCP bug In-Reply-To: <199812021647.LAA09094@lakes.dignus.com> References: <199812021636.JAA06068@mt.sri.com> <199812021647.LAA09094@lakes.dignus.com> X-Mailer: VM 6.34 under 19.16 "Lille" XEmacs Lucid Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > > That's pretty strange. So the router can't make TCP connections to > > > these sites either? > > > > No, the router can, but any machines hung off it's ethernet can't. On a > > whim (based on a hint I got from Karl Peilorz) I changed the MTU on the > > router (which is running SLIP to get to the net) from 552 to 1500, and > > now things work. > > > > The strange things is that that the mtu of the SLIP interface if/was 552 > > and all traffic that originated on that box was fine, and the mtu on the > > ethernet interface was 1500, and traffic generated from there did not > > work. > > > > I would have thought that you wouldn't need to fragment any packets that > > had a mtu of 552 to stick it on an ethernet with an mtu of 1500. > > ... > > Just to add to this; I've got exactly the same symptoms; which I previously > reported. > > On my internal network; I can't get to some sites (www.aol.com being > the best example.) > > But, If I'm on the gateway machine - it has no problems getting there. > > Thus, I was implicating natd. But, I don't use natd in my network. All of my boxes have real registered IP address. > I'm betting there's something going on with natd and packet fragmentation. I'll bet something else is going on. > Several people unsuccessfully tried to duplicate my problem; but I'm > wondering now if they were using PPP or something else that had a higher > MTU, and, thus, didn't fragment any packets. I suspect it may have something to do with PPP's mtu vs. SLIP's mtu. Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message