If you run into a problem where your dnsmasq DNS server is not responding to dns queries from separate subnets than the DNS server’s subnet, try setting the listen-address to the DNS server’s IP (e.g. where you’re running dnsmasq).
On the Ubiquiti EdgeRouter Lite (which is based on mips Debian wheezy) the file to change is:
/etc/dnsmasq.d/local.conf
(make it if it doesn’t exist)
add this to that file:
listen-address=<DNS-SERVER-IP>
Where <DNS-SERVER-IP> is the IP of your machine that’s running dnsmasq.
If you’re running dnsmasq from the command line, without using the conf files, add this parameter
--listen-address <DNS-SERVER-IP>
Best tip ever!!