Multiple dns servers override /tmp/resolv.conf

Installing and Using OpenWrt Network and Wireless Configuration
1

I have setup 2 distinct dnsmasq instances for each network:

/etc/config/dhcp

config dnsmasq 'dnsmasq_lan'
        option domainneeded '1'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option domain 'lan'
        option local '/lan/'
        option expandhosts '1'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp_lan.leases'
        option noresolv '1'
        option nonegcache '1'
        option cachesize '0'
        option localservice '1'
        option logdhcp '1'
        list interface 'lan'
        list server 1.1.1.2
        option confdir '/tmp/dnsmasq.d'

config dnsmasq 'dnsmasq_guest'
        option domainneeded '1'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option domain 'guest'
        option local '/guest/'
        option expandhosts '1'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp_guest.leases'
        option noresolv '1'
        option nonegcache '1'
        option cachesize '0'
        option localservice '1'
        option logdhcp '1'
        list interface 'lan'
        list server 1.1.1.3
        option confdir '/tmp/dnsmasq.d'

I noticed that this configuration will overwrite the file `/tmp/resolv.conf`, in the order of how they appear in the configuration.

Now, when we make DNS queries from the router itself, it simply look at /etc/resolv.conf , which happens to be a symbolic link to `/tmp/resolv.conf`.

I do not want the last configured dnsmasq instance in my configuration to dictate what the router itself uses as DNS. I want it to be the first instance in my configuration. What is the clean way to do this?

I could of course reverse my configuration, but I’d like to learn the proper way to do this. I have a lingering doubt that the fact both dnsmasq override the same `/tmp/resolv.conf` also mean the configuration is actually incorrectly intertwined (does the first dnsmasq instance actually use the second dnsmasq’s config?)

2

If you want stable configurations you have to run a dnsmasq instance per network configured with its forwarders set each, like quad9 or cloudflare family .3 depending on what you expect from the guest....

1 Like
3

Hey, thanks for that. I am not clear on what that means exactly though, could you clarify?

4

First set forwarders 1.0.0.3 / 1.1.1.3 in DHCP & DNS
Nothing will rewrite them.
See here - you have to edit file manually to make it double...