From owner-freebsd-questions@FreeBSD.ORG Thu Apr 19 12:22:13 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 43B8F16A403 for ; Thu, 19 Apr 2007 12:22:13 +0000 (UTC) (envelope-from wmoran@potentialtech.com) Received: from mail.potentialtech.com (internet.potentialtech.com [66.167.251.6]) by mx1.freebsd.org (Postfix) with ESMTP id 17FF813C448 for ; Thu, 19 Apr 2007 12:22:12 +0000 (UTC) (envelope-from wmoran@potentialtech.com) Received: from vanquish.pgh.priv.collaborativefusion.com (pr40.pitbpa0.pub.collaborativefusion.com [206.210.89.202]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.potentialtech.com (Postfix) with ESMTP id 33AF7EBC78; Thu, 19 Apr 2007 08:22:12 -0400 (EDT) Date: Thu, 19 Apr 2007 08:22:11 -0400 From: Bill Moran To: Zhang Weiwu Message-Id: <20070419082211.4de04b69.wmoran@potentialtech.com> In-Reply-To: <1176949451.7739.15.camel@joe.realss.com> References: <1176949451.7739.15.camel@joe.realss.com> X-Mailer: Sylpheed 2.3.1 (GTK+ 2.10.11; i386-portbld-freebsd6.1) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: dhcpd assign duplicated IP address X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Apr 2007 12:22:13 -0000 In response to Zhang Weiwu : > > P.S. In recent days we some times got another network problem and I'm > not sure if it's related to this DHCP server behavior. It happens on > both Linux and Windows hosts that a host suddenly is no longer > accessible (Ping no response). Check 'arp -a' on other hosts shows the > host being accessed have wrong Mac Address. e.g. yesterday > 218.193.55.195 suddenly become in-accessible, this host is Linux and we > got this behavior on a nearby host: > > sappho # arping 218.193.55.195 > Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.638ms > Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.637ms > Sent 113 probes (1 broadcast(s)) > Received 113 response(s) > sappho # arp -a 218.193.55.195 > ? (218.193.55.195) at 00:02:2A:C1:53:87 [ether] on eth0 > > arping reply is different from arp cache. This host become accessible > the next day. Strange. Are these two problems related? You have something seriously wrong somewhere. They may be related but there's not enough information here to be sure. Consider installing arpwatch on one or more systems and see if the reports it sends narrow down the problem. -- Bill Moran http://www.potentialtech.com