Date: Thu, 11 Apr 2002 13:51:10 +1000 From: "Arkadi Kosmynin" <ank@bigpond.net.au> To: <freebsd-net@freebsd.org>, <bv@wjv.com> Subject: RE: Need help. A system stops responding to network requests periodically. Message-ID: <OPEKLGNIBDIHJCIEIOPFEEKLCPAA.ank@bigpond.net.au> In-Reply-To: <20020410131829.GA40130@wjv.com>
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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
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