From owner-freebsd-questions@FreeBSD.ORG Wed Aug 15 02:10:22 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 0BA4516A41B for ; Wed, 15 Aug 2007 02:10:22 +0000 (UTC) (envelope-from on@cs.ait.ac.th) Received: from mail.cs.ait.ac.th (mail.cs.ait.ac.th [192.41.170.16]) by mx1.freebsd.org (Postfix) with ESMTP id 5519413C46C for ; Wed, 15 Aug 2007 02:10:20 +0000 (UTC) (envelope-from on@cs.ait.ac.th) Received: from banyan.cs.ait.ac.th (banyan.cs.ait.ac.th [192.41.170.5]) by mail.cs.ait.ac.th (8.13.1/8.12.11) with ESMTP id l7F2ABfJ033621 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 15 Aug 2007 09:10:11 +0700 (ICT) Received: (from on@localhost) by banyan.cs.ait.ac.th (8.13.3/8.12.11) id l7F2A9iU007894; Wed, 15 Aug 2007 09:10:09 +0700 (ICT) Date: Wed, 15 Aug 2007 09:10:09 +0700 (ICT) Message-Id: <200708150210.l7F2A9iU007894@banyan.cs.ait.ac.th> From: Olivier Nicole To: lflacayo@cps.k12.il.us In-reply-to: (lflacayo@cps.k12.il.us) References: X-Virus-Scanned: on CSIM by amavisd-milter (http://www.amavis.org/) Cc: freebsd-questions@freebsd.org Subject: Re: Question about failover with ISC DHCP 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: Wed, 15 Aug 2007 02:10:22 -0000 Hi Luis, > I am looking to replace my current DHCP server with the ISC. Right now > I have to servers which are working with split scopes. Some of my > schools need over 600 IP's, so I have the school with a 255.255.240.0 > which give them 16 Class C, network, so to avoid conflicts I assign the > 3 lower to one server and the 3 highest to the other.=20 This part is really not clear: you have 16 class C, and you assing 3 and 3? What about the 10 others? > Now comes the question, in the following section there is a split of > 128. If I give a range of 3 class C's do I set this value to 128 or > (128*# Class C Networks)? =20 Fron man dhcpd.conf The split statement split index; The split statement specifies the split between the primary and sec- ondary for the purposes of load balancing. Whenever a client makes a DHCP request, the DHCP server runs a hash on the client identifica- tion. If the hash comes out to less than the split value, the pri- mary answers. If it comes out to equal to or more than the split, the secondary answers. The only meaningful value is 128, and can only be configured on the primary. This is certainly not giving much information, but they suggest you use 128, so try with 128 first. I'd suggest that you let the load balancing run for a while, then you can see how many clients are served by each DHCP server and you may try to fine adjust the split value. I have been using fail-over while I was preparing a new DHCP server recently (so the clients could start using the new server and the leases were transfered from the old to the new machine) and it was really seamless. Best regards, Olivier