[Dnsmasq-discuss] dnsmasq: routing non /24 reverse in-addr.arpa requests

[Albert ARIBAUD]

Hi Alessandro,

Le Sun, 28 Aug 2016 11:33:02 +0200
Alessandro Bottonelli <alessandro at bottonelli.it> a écrit:

> Hi,
> 
> very new to dnsmasq, and also very impressed. I replaced bind last
> night 'cause I needed to route different subnets reverses to
> different name servers. Not a clean setup, I know. But that's what my
> Customer has been doing over the last twenty years. Cannot do
> anything about it.
> 
> Here's the current /etc/dnsmasq.conf content (I added the line
> numbers):
> 
> -----
> 1.  # routing PTR queries to nameservers:
> 2.  server=/50.150.10.in-addr.arpa/10.150.50.17
> 3.  server=/51.150.10.in-addr.arpa/10.150.50.17
> 4.  server=/52.150.10.in-addr.arpa/10.150.50.17
> 5.  server=/53.150.10.in-addr.arpa/10.150.50.17
> 6.  server=/54.150.10.in-addr.arpa/10.150.50.17
> 7.  server=/156.240.10.in-addr.arpa/10.150.50.17
> 8.  server=/157.240.10.in-addr.arpa/10.150.50.17
> 9.  server=/158.240.10.in-addr.arpa/10.150.50.17
> 10. server=/129.240.10.in-addr.arpa/10.240.129.113
> 11. # anything else not defined above (strict-order is set)
> 11. server=/10.in-addr.arpa/10.159.59.41
> ----
> 
> The issue is with line 7, actually 10.240.156.x IS NOT a /24 net. I 
> tried different syntax forms, I searched, but could not find a way to 
> tell dnsmasq about that.

[10.240.156.x looks like a /24 (sub)net to me, what with three bytes out
of four being constant. Do you mean the third byte may be something
else than 156? Or is x being restricted to less than whole 0..255
range?]

> Is it possible?

Can you use rev-server? The manpage gives an example with a subnet size
for rev-server (whereas it does not give any size for server). Maybe
other values than 24 work too -- I haven't checked the source code,
only the manpage.

> Or alternatively; is there a way to tell dnsmasq to ignore NXDOMAIN
> from previous servers and keep asking? I KNOW, intellectually very
> wrong. But real life is real life :-)
> 
> Thanks in advance for any help.

Amicalement,
-- 
Albert.