From owner-freebsd-net Tue Feb 26 15:58:14 2002 Delivered-To: freebsd-net@freebsd.org Received: from gw.gbch.net (gw.gbch.net [203.143.238.93]) by hub.freebsd.org (Postfix) with SMTP id 0656637B41A for ; Tue, 26 Feb 2002 15:58:09 -0800 (PST) Received: (qmail 615 invoked by uid 1001); 27 Feb 2002 09:51:27 +1000 X-Posted-By: GJB-Post 2.23 27-Nov-2001 X-Operating-System: FreeBSD 4.2-RELEASE i386 X-Uptime: 48 days, 16:12 X-Location: Brisbane, Australia; 27.49841S 152.98439E X-URL: http://www.gbch.net/gjb.html X-Image-URL: http://www.gbch.net/gjb/gjb-auug048.gif X-GPG-Fingerprint: EBB2 2A92 A79D 1533 AC00 3C46 5D83 B6FB 4B04 B7D6 X-PGP-Public-Keys: http://www.gbch.net/keys.html Message-Id: Date: Wed, 27 Feb 2002 09:51:26 +1000 From: Greg Black To: "Matthew Emmerton" Cc: freebsd-net@freebsd.org Subject: Re: ppp -nat fails with adsl, but ok with modem References: <00ad01c1bd71$98237820$1200a8c0@gsicomp.on.ca> <001e01c1bd8a$22f347b0$1200a8c0@gsicomp.on.ca> In-reply-to: of Mon, 25 Feb 2002 10:20:05 +1000 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Greg Black wrote: | "Matthew Emmerton" wrote: | | | > | > I've had ppp -nat working just fine over a normal modem link, | | > | > but it is not working at all well on my ADSL link to the same | | > | > provider. | | > | > | | > | > To quantify "not working at all well", although I can ping and | | > | > traceroute ok from the hosts on my LAN, HTTP and FTP traffic is | | > | > so slow and bursty as to be useless. Clicking on a link with | | > | > Netscape will see short bursts of data with long periods (of a | | > | > minute or more) where it says "stalled". | | > | > | | > | > Clicking on from | | > | > my gateway host gets the page in an eye-blink, but on the NAT | | > | > hosts, it will take 40 seconds to load the top banner and the | | > | > "FreeBSD GNOME News Flash" heading, then another delay of 40 or | | > | > so seconds before the rest of the page will be displayed. Even | | > | > then, Netscape thinks it has stalled and keeps waiting for the | | > | > last bit of data. | | > | > | | > | > With FTP, a small transfer (e.g., a directory listing of / on | | > | > ftp.freebsd.org) will complete normally; but something slightly | | > | > larger (e.g., a listing of /pub/FreeBSD on the same server), | | > | > will produce: | | > | > | | > | > ftp> cd /pub/FreeBSD | | > | > 250 CWD command successful. | | > | > ftp> dir | | > | > 200 PORT command successful. | | > | > 150 Opening ASCII mode data connection for '/bin/ls'. | | > | > ftp: netin: Connection reset by peer | | > | > 226 Transfer complete. | | > | > ftp> quit | | > | > 421 Timeout (60 seconds): closing control connection. | | > | > | | > | > If I do the same things from the host that is connected to the | | > | > modem(s), everything works fine, for both types of connections. | | > | > | | > | > I'm finding this very frustrating, and I'm wondering if there's | | > | > something weird about PPPoE with the ADSL link that needs some | | > | > special magic in order for things to work properly. | | > | > | | > | > If anybody can point me at the truth, I'd be most grateful. | > | > | | > | > Alternatively, if anybody can suggest steps I could take to | | > | > identify the nature of the problem, that would also be most | | > | > welcome. | | > | | | > | What version of FreeBSD are you using? The ppp included in early 4.x | | > | distributions doesn't have the TCP MSS fixup code that is required to | | > | make | | > | things work properly with a PPPoE connection, and cause the kinds of | | > | symptoms that you describe. | | > | | > The NAT box is running 4.2-RELEASE -- is that a problem? | | | | Yes. This problem was first fixed in 4.2-STABLE. There are two safe ways to | | fix this: | | - upgrade to a newer -RELEASE or -STABLE | | - run the tcpmssd program (which is in the ports collection - | | /usr/ports/net/tcpmssd) | | I'll try tcpmssd first -- I have some other systems in a similar | situation that are running 4.1-RELEASE and can't be upgraded, so my | solution needs to work for them too. Thanks for the information. OK, I have setup tcpmssd on my 4.1-R and 4.2-R NAT boxes and it seems to be doing the job, but I am seeing some worrying log messages on one of the machines: tcpmssd: write to divert socket failed: Message too long There have been 26 of these over 10 hours during which 4 Mbytes of data in 21k packets have been through the divert rule. Is there a fix, or do I just ignore it in the hope that things will sort themselves out? Greg To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message