From owner-freebsd-questions Fri Oct 5 15: 2:47 2001 Delivered-To: freebsd-questions@freebsd.org Received: from monk.via.net (monk.via.net [209.81.2.10]) by hub.freebsd.org (Postfix) with ESMTP id 6B93037B403 for ; Fri, 5 Oct 2001 15:02:44 -0700 (PDT) Received: (from joe@localhost) by monk.via.net (8.11.1/8.11.0) id f95M4CJ73523 for questions@freebsd.org; Fri, 5 Oct 2001 15:04:12 -0700 (PDT) (envelope-from joe) From: Joe McGuckin Message-Id: <200110052204.f95M4CJ73523@monk.via.net> Date: Fri, 5 Oct 2001 15:04:12 -0700 (PDT) To: questions@freebsd.org Subject: FTP server problem ? X-Mailer: Ishmail 1.3.1-970608-bsdi MIME-Version: 1.0 Content-Type: text/plain Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG I have approx. 100 users coming in to my network via PPPOE. There's an interesting anomaly that shows up when any of these users attempt to retrieve a file from one of our ftp servers. (I verified this with my linux laptop also) The typical setup is as follows: A B C D PC --- PPPOE Router ------ Gige Switch -(fiber)- Gige Switch --- Cisco 7200 --- Switch --- Cisco 7200 --->>> Internet LinkSys, etc PPPOE sessions | Performs NAT also terminate here. | | FTP server FTP downloads from ftp.mozilla.org average about 4Mbits/sec FTP downloads from my ftp server average about 90 kbits/sec Scenario #1: PC or linux laptop at location 'A' (Using PPPoE and NAT) When performing downloads from mozilla.org, the PPPOE router activity light blinks constantly, indicating uninterrupted thruput. When downloading from my ftp server, there a flurry of blinks, then a 5 second pause. This sequence repeats until the transfer is completed. Scenario #2: Linux laptop at location 'B', (No PPPoE or NAT involved) Ftp tranfers to my ftp server run at about 10 Mbits/second Ftp transfers to mozilla.org run at about 4 Mbits/sec The questions are: 1) When ftp'ing behind the PPPoE router, why is my ftp server exhibiting slow transfers with multi-second delays between packets? Why doesn't mozilla.org exhibit this behavior? 2) What tcp/ip setting could the PPPOE router impose that would cause this poor performance by my ftp server? MTU setting? 3) What further staps can I take to debug this? Are there any tcp debug flags or ftp setting I could try ? Thanks, Joe -- Joe McGuckin ViaNet Communications 994 San Antonio Road Palo Alto, CA 94303 Phone: 650-213-1302 Cell: 650-207-0372 Fax: 650-969-2124 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message