From owner-freebsd-net@FreeBSD.ORG Tue Mar 18 20:49:00 2008 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 23CA8106567D for ; Tue, 18 Mar 2008 20:49:00 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from mail.farley.org (farley.org [67.64.95.201]) by mx1.freebsd.org (Postfix) with ESMTP id DE8488FC1B for ; Tue, 18 Mar 2008 20:48:59 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from thor.farley.org (thor.farley.org [192.168.1.5]) by mail.farley.org (8.14.2/8.14.2) with ESMTP id m2IKmvl0034481; Tue, 18 Mar 2008 15:48:57 -0500 (CDT) (envelope-from scf@FreeBSD.org) Date: Tue, 18 Mar 2008 15:48:57 -0500 (CDT) From: "Sean C. Farley" To: "Bruce M. Simpson" In-Reply-To: <47DE4E96.8080507@FreeBSD.org> Message-ID: References: <47DE4E96.8080507@FreeBSD.org> User-Agent: Alpine 1.00 (BSF 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on mail.farley.org Cc: freebsd-net@FreeBSD.org Subject: Re: Frequent pauses with Linux-based router 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 Mar 2008 20:49:00 -0000 On Mon, 17 Mar 2008, Bruce M. Simpson wrote: > Sean C. Farley wrote: >> I have noticed that with a Linux-based Netgear DG834G (DSL modem) >> frequent pauses (example[1]) between external systems and 7-STABLE >> (March 14th). At first, I thought it was ipfilter or ipnat, but I >> took those out of the picture by activating telnet on the router and >> connecting directly to it. Even running "ls /usr/sbin" on the router >> would pause occasionally. I did not (or did not recall) have these >> problems with 6-STABLE (post 6.2). I switched out the NIC (FA-311 >> (sis) to a FA-310 (dc)), cable and tried different ports on the modem >> by which to connect. I also tried disabling all RFC sysctl's and >> SACK. Nothing helped. >> >> Finally, I brought out an old DSL modem (SpeedStream 5660). This >> fixed the issue. I think this maybe a specific issue between Linux >> (2.4.17_mvl21-malta-mips_fp_le) and FreeBSD 7. Is there anything >> else I may test to see what is happening? > > OT: Hang on, are you saying you're running a MIPS MALTA targeted Linux > kernel on a Netgear DG834G? That would be interesting as a test > platform for FreeBSD/mips, considering the platform support for Malta > is already there. I had a go at doing the Broadcom Sentry5 SoC last > year but hadn't finished anything. Here is a bit of information about it from /proc: # cat cpuinfo processor : 0 cpu model : MIPS 4KEc V4.8 BogoMIPS : 211.35 wait instruction : no microsecond timers : yes extra interrupt vector : yes hardware watchpoint : yes VCED exceptions : not available VCEI exceptions : not available # cat meminfo total: used: free: shared: buffers: cached: Mem: 14712832 9666560 5046272 0 1130496 3694592 Swap: 0 0 0 If I was not using it for my main DSL router, I would consider putting FreeBSD on it. After the frustration I had with it, I did seriously wonder about FreeBSD on it. It would be especially tempting if it would still function as a DSL router along with the web interface. :) It has wireless, but I have that disabled. If you are interested in more specs, I can cat /proc for you. > Long shot, but are 802.3 pause frames appearing anywhere, ie can you > test with a crossover cable? > Have you done a BER test with UDP or something like that to try to > rule out non-TCP protocols? Well, with help on IRC from Robert Watson and others, I was able to "fix" it. An ICMP test showed that there were occasional pauses and packet loss. The fix: use 100Mb instead of 10Mb. :) For some reason I do not recall, I had forced the interface connected to the DSL router to 10Mb. When I noticed XP did not have the same problem and that it had a 100Mb connection to the router, I found and removed the "media 10baseT/UTP mediaopt full-duplex" from /etc/rc.conf for the interface. That appears to have fixed it. I have never heard of pause frames. Interesting. Also, I do not recall seeing anything unusual with tcpdump (using "host dsl" expression I think). The pause always seemed to be for packets from the router to the computer. Sean -- scf@FreeBSD.org