Date: Mon, 29 Nov 2004 21:57:17 -0000 (GMT) From: "David Jenkins" <david.jenkins@gmail.com> To: "Jonathon McKitrick" <jcm@FreeBSD-uk.eu.org> Cc: freebsd-questions@freebsd.org Subject: Re: Caching DNS for dialup Message-ID: <1235.10.0.0.2.1101765437.squirrel@10.0.0.2> In-Reply-To: <20041129204452.GI73697@dogma.freebsd-uk.eu.org> References: <20041123233501.GA82229@dogma.freebsd-uk.eu.org> <5557305861.20041124004849@hexren.net> <20041124000014.GA83249@dogma.freebsd-uk.eu.org> <8763344284.20041124022927@hexren.net> <20041124141737.GA11648@dogma.freebsd-uk.eu.org> <41A49F58.4020000@circlesquared.com> <20041124154628.GE11648@dogma.freebsd-uk.eu.org> <41A4BFC8.8070702@circlesquared.com> <20041129204452.GI73697@dogma.freebsd-uk.eu.org>
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On Mon, 29 November, 2004 20:44, Jonathon McKitrick said: > On Wed, Nov 24, 2004 at 05:07:20PM +0000, Peter Risdon wrote: > : A caching DNS server would help conserve bandwidth on a dialup > : connection - I generally run one myself with any connection with > limited > : bandwidth. > > After RTFM, I believe I have it up and running. ;-) > > Named is running, but how can I be sure the caching is working? > > Also, does it make sense to do this on each box, or just the gateway? You can try a few digs and see what the response time is. i.e. pick a hostname that you know you haven't visited since the caching DNS server has been running. Then do a dig. >From the gateway. # dig @localhost somehostname then do it again, and see how different the response time is. e.g. on mine: > dig @localhost www.bbc.co.uk <snip> ;; Query time: 59 msec ;; SERVER: 127.0.0.1#53(localhost) and then again ... ;; Query time: 2 msec ;; SERVER: 127.0.0.1#53(localhost) then try this from your client machines on your network (with different domain names etc...) This is a very simple way of doing it. Of course, you could also sniff the gateway's external network interface for DNS traffic and try a hostname you know you should have in your cache. In my case: # tcpdump -i xl0 port 53 There's probably loads of better ways of doing it, but these are nice and simple. Cheers, David
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