[modervador]

Good people of the forum, please consider this. It seems there is some confusion between options

Setup : Basic Setup : Network Address Server Settings (DHCP) : "Use DNSMasq for DNS" (checkbox)
Services : Services : DNSMasq : "Local DNS" (enable/disable radio buttons)

Of those two, I believe that "Use DNSMasq for DNS" is the only one relevant to DNSMasq, i.e., the "Local DNS" option does nothing for DNSMasq. On my routers (build 15230 mini), I have looked at /tmp/dnsmasq.conf and /tmp/resolv.dnsmasq, and I see no change in these files when changing the "Local DNS" option. I think I've tracked down the source of this. The nvram variable in question here is "dns_local", as can be seen in

http://svn.dd-wrt.com/browser/src/router/udhcpd/config/dhcpd.webservices which is loaded by Services.asp.

Now look in

http://svn.dd-wrt.com/browser/src/router/services/services/udhcpd.c
http://svn.dd-wrt.com/browser/src/router/services/services/dnsmasq.c

and see that dns_local is used by uDHCPd but completely ignored by DNSMasq. Therefore, the "Local DNS" option is for uDHCPd and not DNSMasq.

Well, this is kind of funny, because if DNSMasq is disabled by these chechboxes/buttons,

Setup : Basic Setup : Network Address Server Settings (DHCP) : "Use DNSMasq for DHCP" (checkbox)
Setup : Basic Setup : Network Address Server Settings (DHCP) : "Use DNSMasq for DNS" (checkbox)
Services : Services : DNSMasq : "DNSMasq" (enable/disable radio buttons)

then the WebUI hides the "Local DNS" option at the only time that it is relevant, which is when uDHCPd must handle DNS. The code in udhcpd.c seems to show that uDHCPd does not load if "Use DNSMasq for DHCP" is checked, so there is no way to use DNSMasq for DHCP and use uDHCPd for DNS (not that you would want to do that).

As a first step to minimise this confusion, I believe the "Local DNS" option should be removed from the "DNSMasq" fieldset box on the Services page. Instead, it should show "Local DNS" and "Additional DHCPd Options" in a separate fieldset with the legend "uDHCPd", in the same way "DNSMasq Enable/Disable", "No DNS Rebind" and "Additional DNSMasq Options" are in a fieldset with the legend "DNSMasq".

Comments?

(In case you're looking for it, int dns_to_resolv(void) is found in http://svn.dd-wrt.com/browser/src/router/libutils/bcmutils.c )

[SmartGeek]

thank you for your information. And I agree, this is very confusing.

It doesn't help that the dd-wrt documentation says to click on Local DNS when setting up DNSMasq.

http://www.dd-wrt.com/wiki/index.php/DNSMasq_as_DHCP_server

[PushedChip649]

Thank you very much for clearing this up modervador. I had played around with the dnsmask options for "local dns" settings a while back.

I few days ago when I came to try and connect to a local NAS querying by name my local DNS couldn't find it anymore until you clearly explained this.

Thanks a million

[ghoffman]

i hope this i addressed. I have tried to use udhcpd instead of dnsmasq, partly because the dhcp lease times are then usefully displayed in the gui. the other option would be for the devs to fix the dnsmasq lease time display. these are old issues that seem to have been dropped; the solutions are apparently not complex and a little code cleanup could solve years of frustions.

does anyone have influence of knowledge about how to get these changes implemented?

[wirerydr]

[ghoffman]

[BobLoblaw1122]

BrainSlayer stated that the "Local DNS" does have an effect with DNSMasq:

http://svn.dd-wrt.com/ticket/4701