From owner-freebsd-net Wed Apr 10 20:52:55 2002 Delivered-To: freebsd-net@freebsd.org Received: from mta02bw.bigpond.com (mta02bw.bigpond.com [139.134.6.34]) by hub.freebsd.org (Postfix) with ESMTP id 6555537B404 for ; Wed, 10 Apr 2002 20:52:49 -0700 (PDT) Received: from home ([144.135.24.84]) by mta02bw.bigpond.com (Netscape Messaging Server 4.15 mta02bw Feb 26 2002 03:44:21) with SMTP id GUDXFX00.234; Thu, 11 Apr 2002 13:52:45 +1000 Received: from CPE-144-137-1-211.vic.bigpond.net.au ([144.137.1.211]) by bwmam06.mailsvc.email.bigpond.com(MailRouter V3.0j 47/216097); 11 Apr 2002 13:52:42 Reply-To: From: "Arkadi Kosmynin" To: , Subject: RE: Need help. A system stops responding to network requests periodically. Date: Thu, 11 Apr 2002 13:51:10 +1000 Message-ID: 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 IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: <20020410131829.GA40130@wjv.com> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 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 Hi Bill, Thanks for a hint. My network consists of three computers connected via a 10 Mbps hub. I don't think that this is a hardware problem. I never experienced any networking problems except in this situation. Besides, netstat shows very low number of bad segments and segment retransmissions. That, I believe, indicates a healthy network. Any other ideas? Thank you, Arkadi. > -----Original Message----- > From: owner-freebsd-net@FreeBSD.ORG > [mailto:owner-freebsd-net@FreeBSD.ORG]On Behalf Of Bill Vermillion > Sent: Wednesday, April 10, 2002 11:18 PM > To: freebsd-net@freebsd.org > Subject: Re: Need help. A system stops responding to network requests > periodically. > > > On Wed, Apr 10, 2002 at 11:06:09PM +1000, Arkadi Kosmynin spewed forth: > > > I really can not explain this. We are stress testing a server. We > > use the following configuration: the server runs on a FreeBSD box > > (or Linux, with a similar effect). A multithreaded tester program > > runs on a Win2K box and emulates random multiuser activity. The > > FreeBSD box stops responding to network requests every 20-30 > > minutes. I can't even connect to its FTP server. If I don't > > touch it, it does not "unstuck" for quite a while. But, if I do > > something with it, like start a Web browser on it and access the > > server, or just do netstat, it became active again shortly. > > > Can anyone explain this? Is it some form of protection from denial > > of service attack? The tester program generates a lot of requests, > > and does it very fast, so, it does look like an attack. > > You didn't say a thing about your network. Sometimes the plain > stopping can be a result of automatic-sensing and > automatic-negotiation if you do not have everything fixed. > > Take a look at this and understand the failure modes > > http://www.cisco.com/warp/public/473/46.html > > While it is targeted to the Cicso switches the same advice applies > to most things. > > I'm not saying this IS the problem you are having but since it is > on the same HW with two OSes this needs to be verfied. > > Bill > > -- > Bill Vermillion - bv @ wjv . com > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message