Thanks Ted - answers are embedded - Joe >Date: Wed, 20 Aug 2008 15:00:16 -0400 >From: Ted Roche >To: [EMAIL PROTECTED] >cc: >Subject: Re: [NF] Small LAN configuration for failsafe DNS > >On Wed, Aug 20, 2008 at 1:12 AM, Joe Yoder <[EMAIL PROTECTED]> wrote: > >> I am running Server 2003 on a small LAN of about 10 machines. Internet >> access is via cable modem connected through a router to all machines. I >> need to have the machines use the DNS server in the 2003 box while that box >> is functional. If the 2003 box is down, the router should handle the DNS. > >Why should the 2003 server be down? Is that a common problem for you? >Generally speaking, you shouldn't use an unreliable machine as a DNS >server.
2003 is the machine I use to experiment with so I may be making changes that would prevent Internet only users from accessing the Internet. Also I am out of the office for weeks at a time and if something happens to 2003 I prefer to take care of it myself when I get back rather than paying someone to come in and fix it so the Internet only machines can still work. > >> My current router's DHCP server has no setting to control the Preferred or >> Alternate DNS server values it distributes. > >Most _clients_ do not handle DNS this way. If a DHCP server supplies >them with two or three DNS servers to use, they rotate amongst them. >There isn't a primary and an alternate or backup. This can lead to >hard to troubleshoot problems, when every third request a workstation >makes fails, if the DNS server its supposed to query is unavailable. >So, if your server is likely to be down, it is better to not list it >as a DNS source and instead let the router handle all the requests. If >the router's down, they're not going to get far anyway, right? I had never read about or experienced this behavior. Under XP Home when I do an IPCONFIG /ALL I see a list of DNS server addresses without the Preferred or Alternate designations but when I do repeated NS lookups it appears that the system always uses the Preferred DNS server defined on the general tab of the Internet Protocol(TCP/IP) Properties panel under the Local Area Connection. > >> Does someone know of a router with a built in DHCP server that does support >> those settings? > >Fail-over DNS is more complex that what you are asking for, and >probably more complex than you need. > >> I expect there would be a way to setup a Linux box to do the job but I would >> prefer avoiding adding any equipment with rotating parts. > >My favorite Linux box for DNS and DHCP and much more is the Linksys >WRTLS54GS. There are no rotating parts. That sounds interesting. Does one need to flash the firmware or does the box ship with Linux? > >> Another possibility would be to have two DHCP servers (router and 2003) with >> non overlapping ranges. Is there a way to ensure that the 2003 one would >> always win when it is running? Might a switch between the router and the >> rest of the LAN add enough delay to have 2003 get there first? > >You don't specify what kind of router you are dealing with, but many >can be configured with "smart" software that can act as a caching DNS >server for the Windows 2003 box and also cache the DNS services you >get from the internet. That way, all workstations can query the >router, and the router will query and update from the W3K3 box if it >can't answer the request itself. The D-Link router I'm using has a Vonage VOIP adapter built in. I checked with their technical support people and they had no suggestions to offer. > >I'm curious, why is it the W2K3 server has to act as DNS? And why is >it that it is sometimes not available? I've got W2K3 boxes at a couple >of clients with 100+ day uptimes... The 2003 box sets up an active directory that several machines authenticate to. I had problems with connections dropping before I setup the domain machines to use the 2003 DNS server. I also need a special zone to handle local access to a dynDNS address that resolves to the 2003 box. > > >-- >Ted Roche >Ted Roche & Associates, LLC >http://www.tedroche.com > > [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[EMAIL PROTECTED] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
