[Dnsmasq-discuss] OS X hosted dnsmasq for AD SRV records

richardvoigt at gmail.com richardvoigt at gmail.com
Mon Nov 22 21:44:51 GMT 2010


Don't know the answer to your question, just wanted to point out that
your other server is not actually returning them in random order.
They are always in the same order but are rotated, and typically
subsequent queries rotate the list by one to achieve load balancing.

Is load balancing your goal?

On Mon, Nov 22, 2010 at 3:35 PM, Peet McKinney <lists at peetinc.com> wrote:
> All,
>
> dnsmasq has been an absolute life-saver in my environment. OS X Directory services isn't playing nicely with GC discovery in my Active Directory environment, so I've brought up a couple instances of dnsmasq to help force it into being a good citizen.
>
> I've compiled dnsmasq on 10.6.4 from the 2.55 source and configured it to respond correctly to my SRV lookups. I've also installed the launchd plist. (Though I have to wonder the value of having that plist configured with '--log-queries' and '--log-facility=/var/log/dnsmasq.log' by default. Admittedly, I'm an idiot for not checking and ending up with a 24GB dnsmasq.log, but considering there's not a default rotation for the log it seems a bit of an odd choice for a default launchd setup.)
>
> Since cleaning up my silly logging issues, I'm left with what my simply be a standard behavior of dnsmasq, but one that I'd really like to find a way around.  When I query SRV records that are in my dnsmasq config, they are *always* returned in the same order with no randomization. Please see below:
>
> jodr:~ jadmin$ host -t SRV _gc._tcp.umontana.edu
> _gc._tcp.umontana.edu has SRV record 0 100 3268 dbsaddc3.dbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc1.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc0.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 msodc13.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc5.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc2.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc2.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc0.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc2.umontana.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc1.umontana.edu.
>
> When I lookup against the AD DNS servers they are randomized.  Of course the results below include servers that I don't want to see returned as results, but you can see that two lookups in quick succession  provided completely different answers:
>
> j010-peet:~ jadmin$ host -t SRV _gc._tcp.umontana.edu
> ;; Truncated, retrying in TCP mode.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc2.umontana.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdcctw.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc2.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc0.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc1.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 flbs-dc01.flbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc1.umontana.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc0.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdccte.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 dbsaddc3.dbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc5.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdch1.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 msodc13.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc2.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umh-st1.helena.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 dbsaddcfm.dbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umh-ap1.helena.campus.
>
> j010-peet:~ jadmin$ host -t SRV _gc._tcp.umontana.edu
> ;; Truncated, retrying in TCP mode.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc2.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mitosdc0.missoula.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc1.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 flbs-dc01.flbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc1.umontana.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 gsdc0.gs.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdccte.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 dbsaddc3.dbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc5.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdch1.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 msodc13.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdcctw.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 mumtdc2.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umh-st1.helena.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 dbsaddcfm.dbsad.umt.edu.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umh-ap1.helena.campus.
> _gc._tcp.umontana.edu has SRV record 0 100 3268 umontanadc2.umontana.edu.
>
> Is there anyway to randomize the answers dnsmasq provides.
>
> Thanks.Peet
>
>
>
>
>
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