From owner-freebsd-questions@FreeBSD.ORG Sat Sep 1 21:52:19 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DCAED16A418 for ; Sat, 1 Sep 2007 21:52:19 +0000 (UTC) (envelope-from fbsd.questions@rachie.is-a-geek.net) Received: from snoogles.rachie.is-a-geek.net (66-230-99-27-cdsl-rb1.nwc.acsalaska.net [66.230.99.27]) by mx1.freebsd.org (Postfix) with ESMTP id ABC9C13C458 for ; Sat, 1 Sep 2007 21:52:19 +0000 (UTC) (envelope-from fbsd.questions@rachie.is-a-geek.net) Received: from localhost (localhost [127.0.0.1]) by snoogles.rachie.is-a-geek.net (Postfix) with ESMTP id C45CD1CC38 for ; Sat, 1 Sep 2007 13:52:18 -0800 (AKDT) From: Mel To: freebsd-questions@freebsd.org Date: Sat, 1 Sep 2007 23:52:16 +0200 User-Agent: KMail/1.9.7 References: <620471.13542.qm@web34613.mail.mud.yahoo.com> <46D9D9F3.3090306@boosten.org> In-Reply-To: <46D9D9F3.3090306@boosten.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200709012352.17359.fbsd.questions@rachie.is-a-geek.net> Subject: Re: how to change isc-dhcp3-server replies? (was: isc-dhcp3-server issues with windows 2000 client) 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: Sat, 01 Sep 2007 21:52:19 -0000 On Saturday 01 September 2007 23:30:27 Peter Boosten wrote: > Joe wrote: > > Hello, after running tcpdump for a while I discoverd what is going on > > with my dhcpd server and why some clients are not able to get an IP > > address from it, in particular windows clients. It turns out it is not > > just win2k but any windows. > > > > It seems that the dhcpd server is replying to the subnet and not the > > broadcast net. So the reply that should be sent to 255.255.255.255:68 is > > sent to 192.168.0.255:68. Then, because the client has no IP address or > > has defaulted it to a 169.x.x.x(MS defaults) it does not seem to be > > getting the reply and thus never gets an address assigned. > > I have no problems running dhcp3 with windows clients at all... As far > as I can tell the broadcast address of a subnet *never* is 255.255.255.255. It is for DHCPDISCOVER, since there is no subnet yet: # dhclient -d fxp0 DHCPDISCOVER on fxp0 to 255.255.255.255 port 67 interval 4 As for the option you're looking for, man dhcpd.conf showed me this: always-broadcast flag; The DHCP and BOOTP protocols both require DHCP and BOOTP clients to set the broadcast bit in the flags field of the BOOTP message header. Unfortunately, some DHCP and BOOTP clients do not do this, and there- fore may not receive responses from the DHCP server. The DHCP server can be made to always broadcast its responses to clients by setting this flag to 'on' for the relevant scope; relevant scopes would be inside a conditional statement, as a parameter for a class, or as a parameter for a host declaration. To avoid creating excess broadcast traffic on your network, we recommend that you restrict the use of this option to as few clients as possible. For example, the Microsoft DHCP client is known not to have this problem, as are the OpenTransport and ISC DHCP clients. Worth a shot :) -- Mel People using reply to all on lists, must think I need 2 copies.