From owner-freebsd-stable Mon Apr 2 16: 8:52 2001 Delivered-To: freebsd-stable@freebsd.org Received: from snapper.lansters.com (21-155-124-64.dsl.lan2wan.com [64.124.155.21]) by hub.freebsd.org (Postfix) with ESMTP id 20D5337B719; Mon, 2 Apr 2001 16:08:48 -0700 (PDT) (envelope-from lucky@lansters.com) Received: from lucky (lucky.lansters.com [10.1.0.2]) by snapper.lansters.com (8.11.2/8.9.3) with SMTP id f32N8gh17482; Mon, 2 Apr 2001 19:08:42 -0400 (EDT) (envelope-from lucky@lansters.com) From: "Jason T. Luttgens" To: "'Doug Hardie'" , Cc: "'Mike Smith'" , "'David W. Chapman Jr.'" Subject: RE: Network performance question Date: Mon, 2 Apr 2001 19:08:14 -0400 Message-ID: <000001c0bbc9$cc97b990$0200010a@lucky> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Ok, I've done some re-testing on the suggestions of a few people. I created a known data set of 500000 packets with a data value in each packet that increments by one. This way I can tell what packets are lost, if any. Interestingly enough, the Linux 2.4.3 kernel captured almost all packets. FreeBSD 4.2 and 3.5.1 were off by 1000+. However - I noticed something while testing. Linux 2.4.3 did not access the drive as much as FreeBSD was. I guess Linux is caching the file more or something...who knows. So I re-performed the tests with output going to /dev/null and looking at the tcpdump and interface counters (I know, it's not the best way, but at this point I was thinking it's the disk I/O that's causing the drops/loss). I tried the test under FreeBSD with the NetGear card too - in addition to the 3COM. It's kinda strange, but when using the NetGear card and outputting tcpdump to /dev/null there were no problems, not even many interface errors (where as writing to a file causes the network to go down and tons of interface errors about halfway through the capture). When outputting tcpdump to /dev/null, performance was comparable +- 5 packets each time between Linux 2.4.3 and FreeBSD. Sometimes FreeBSD got a couple more, sometimes Linux 2.4.3 did. It would seem I need to perform a sustained load test...like spew packets for a day and then compare. Maybe that's what I'll do next. Anyone know what might be going on here? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message