[Dnsmasq-discuss] upstream dns referral?

[john doe]

On 10/3/2019 7:15 PM, bjh wrote:
> Hi,
>
> I have a dnsmasq installation, running on a dedicated raspberry pi, that
> has served me well for almost exactly one year now, until midday
> yesterday when it apparently stopped referring queries to upstream DNS
> servers. I have been relying on this dnsmasq setup to do dhcp and dns
> for my home lan of about 20 clients since Oct 2018. As I said, it has
> worked flawlessly until yesterday. I have of course done restarts and
> power cycles to the pi and dnsmasq service but to no avail.
>
> DHCP and local DNS queries still seem to work on this dnsmasq installation.
>
> I haven't made any changes to my network or this pi lately, so I am
> rather mystified as to what has caused dnsmasq to behave differently all
> of a sudden. As a workaround, I have had to go to important client
> machines on my lan and set them up with OPENDNS DNS addresses so they
> can continue to function while I fix this.
>
> As a complete dnsmasq newbie, I set the dnsmasq up in Oct 2018, with the
> help of an internet article that I can no longer find. It recommended
> leaving /etc/dnsmasq.conf alone and putting all site specific config
> data into /etc/dnsmasq.d/home.dns. This is what I did, see attached.
> File /etc/dnsmasq.conf remains unchanged from how the installer program
> left it, with most if not all features commented out.
>
> The /etc/dnsmasq.d/home.dns file is pretty simple but it doesn't
> explicitly set up any referrals to upstream dns servers.
>
> Quite frankly, I never really understood how dnsmasq knew where to send
> queries it couldn't resolve by itself. It was working, till now, though,
> so I went on to other things and forgot about it.
>
> My question now is this:
>
> What do I need to add to home.dns to explicitly tell dnsmasq the ip
> addresses of upstream DNS server(s) and authorize it to refer locally
> unresolvable queries to it/them?
>
> Other thoughts or observations germane to this mystery would also be of
> interest.
>

On the Dnsmasq server what gives the following command:

$ host google.com


To answer your question:

You will need to use the 'server' directive', something like:

server=<IP-OF-UPSTREAM-DNS-SERVER>


Is there all there is in your home.dns file?
If so,  I would suggest you to get rid of it and start fresh by
modifying '/etc/dnsmasq.conf'.


My guess is that Dnsmasq is not the issue here,, but the file
'/etc/resolv.conf' is not properly populated.

--
John Doe