From owner-freebsd-net Fri Apr 20 13:19:29 2001 Delivered-To: freebsd-net@freebsd.org Received: from ptavv.es.net (ptavv.es.net [198.128.4.29]) by hub.freebsd.org (Postfix) with ESMTP id C009037B43E for ; Fri, 20 Apr 2001 13:19:26 -0700 (PDT) (envelope-from oberman@ptavv.es.net) Received: from ptavv.es.net (localhost [127.0.0.1]) by ptavv.es.net (8.10.1/8.10.1) with ESMTP id f3KKJNc07968; Fri, 20 Apr 2001 13:19:23 -0700 (PDT) Message-Id: <200104202019.f3KKJNc07968@ptavv.es.net> To: "leal" Cc: freebsd-net@FreeBSD.ORG Subject: Re: right In-reply-to: Your message of "Fri, 20 Apr 2001 16:47:51 -0300." <008501c0c9d2$cee98720$1400000a@myway.com.br> Date: Fri, 20 Apr 2001 13:19:23 -0700 From: "Kevin Oberman" Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > From: "leal" > Date: Fri, 20 Apr 2001 16:47:51 -0300 > Sender: owner-freebsd-net@FreeBSD.ORG > > I believe that this question is pertinent in this forum. I have some > wireless-lan's interconected with my principal lan that have internet > access. Without visible answers, all my wireless-lan is with the traffic > terrible!!! lost more lost. 50%, 75% of losses, this started more or less > two days. i know tcpdump, how i use it??? i wanna help for debbug my > network, looking for worms, viruses, i don't know... and i'm in panic. > software??? how can i debbug and looking for bug's??? Before looking at packet dumps, look at interface errors. They may give you a hint. Usually large magnitude losses are the result of an auto-configuration failure that leaves one end of a connection running full-duplex while the other is half-duplex. The full-duplex end will have no collisions (by definition) but will have a lot of other errors. The half-duplex will probably also have a large number of errors, but will also show many collisions. The other thing to look for is bad interconnects. Damaged or poorly crimped cables are a source of these problems. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message