DD-WRT serving additional DNS servers instead of just the router’s IP

dd-wrtdhcpdnsdnsmasqrouter

I have a DD-WRT (using DD-WRT v24SP2-MULTI (03/21/11) std) router set up with DNSMasq to resolve certain domains to internal addresses and pass everything else thru. The router itself is configured to use Google’s public DNS servers to resolve addresses.

My setup screen looks like this:

DDWRT Setup Screen

My problem is that when a DHCP client connects, they get the router plus Google’s two DNS servers as the assigned DNS servers:

DNS servers assigned by DHCP

This is a problem because sometimes wireless clients try to resolve a domain that is supposed to point to an internal IP address and end up getting an external ip instead because for whatever reason their request is sent to 8.8.8.8 instead of to the router.

I don’t want the router to serve anything but its own IP as the DNS server. Is that possible?

Best Answer

It's good that you're using DNSMasq.

You can configure what you want in the Services (> Services) tab, in the DNSMasq > Additional DNSMasq Options box, but first, you'll want to clear those Static DNS fields. Static DNS fields in "Setup > Basic Setup"

Add the following to the DNSMasq options box:

dhcp-option= option:dns-server, 192.168.10.10 # DHCP option 006

server = 8.8.8.8 # DNSMasq will use these servers for forwarding the DNS requests that it can't serve
server = 8.8.4.4