[Dnsmasq-discuss] DHCP DNS Issues

Robert Ferris baffles at gmail.com
Sun Jan 26 21:29:34 GMT 2014

I've got dnsmasq on my router (running tomato), doing DHCP and DNS. Lately,
though, it's not resolving dynaic DHCP hostnames. It resolves hostnames for
static DHCP assignments fine, and everything else seems to work fine, but
it just forwards DHCP hostname DNS requests to the upstream server, which
obviously then returns NXDOMAIN.


Dnsmasq version 2.58  Copyright (c) 2000-2011 Simon Kelley
Compile time options IPv6 GNU-getopt no-RTC no-DBus no-i18n DHCP TFTP
no-conntrack no-IDN

I have a domain set in the conf file (vortex), with expand-hosts,
stop-dns-rebind, rebind-localhost-ok, and dhcp-authoritative.

Here are two example leases from the leases file:

75790 00:0c:29:3f:5e:c0 BAF-VM7 01:00:0c:29:3f:5e:c0
75432 00:0c:29:0b:d8:f0 magnetosphere *

Neither of those hosts resolve. I've tried "BAF-VM7" "BAF-VM7."
"BAF-VM7.vortex" and "magnetosphere" "magnetosphere." and

I've restarted dnsmasq, released/renewed the leases, etc. Occasionally
after restarting or releasing/renewing the lease, it will resolve for a
short while. Sometimes if I try to reverse DNS the IP, it will come back
with the hostname, and then sometimes it will start resolving that hostname
for a short while, but for the most part, it simply doesn't work. This used
to work, with the same configuration, and it was only recently that I
noticed issues with it.

If I run with log-queries and log-dhcp, I can see a machine getting a DHCP
lease, and I can see the lookup requests coming in (and getting forwarded
upstream). If I kill -USR1 it, the dynamic lease hostnames don't appear in
the list, except for hosts where it randomly decides to work.

Tomato isn't maintained for my router anymore, so there aren't any new
versions to update to. Any ideas on getting this working again?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/attachments/20140126/9396ec88/attachment.html>

More information about the Dnsmasq-discuss mailing list