From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Schulman Subject: Re: DNS caching nameserver problem Date: Mon, 30 May 2005 22:05:32 -0400 Message-ID: References: <84bd26ef050530112422641001@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7Bit Return-path: Sender: linux-admin-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-admin-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> I have a DNS caching server that works ok until >> it is rebooted. When this happens it restarts >> normally, except the /etc/resolv.conf file is >> altered and the server stops serving names. (The >> line 'nameserver 127.0.0.1' is missing and other >> namservers appear instead). >> >> The server obtains an address through DHCP and my >> theory is that the DHCP server is providing it >> with DNS servers as well, which it substitutes >> when it probably shouldn't. >> >> I have tried a horrible patch in rc.local, >> stopping named, overwriting resolv.conf with a >> correct copy and restarting, but >> editing the file and restarting 'named' does not >> seem to work 100% of the time, requiring >> sometimes one or two restarts of the service to >> make it serve names for the internal hosts. >> >> What do you think is the problem? >> Is there a workaround? > > Yes, the problem is that your DHCP client is overwriting the > resolv.conf file. How to avoid this, as far as I know, is > distribuition specific. What distribution do you have? pump, for example, includes an option --no-dns that tells it not to overwrite /etc/resolv.conf. I use this along with my cacheing DNS server. I put 'nameserver 127.0.0.1' into /etc/resolv.conf, then I have pump run a postprocessing script that extracts the DNS server information and writes it to /etc/dnsmasq.conf, where dnsmasq (my cacheing name server) looks to find the upstream DNS servers. Good luck, Andrew. - To unsubscribe from this list: send the line "unsubscribe linux-admin" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html