[Dnsmasq-discuss] CNAME resolution

[Simon Kelley]

On 22/10/12 19:46, Doug Carter wrote:
>
> Hi All,
>
> I'm new to dnsmasq and have been running it (version 2.48) on a Linux
> server running CentOS 6, with the following options:
>
>    bogus-priv
>    domain-needed
>    interface=eth0
>    interface=lo
>    no-dhcp-interface=eth0
>
> It's been working great, but ever so often client browsers (Mac/Windows,
> Chrome/Firefox/Safari) hang when trying to resolve CNAMES that many
> sites use to serve static content, for example "cdn.macrumors.com". If
> I do a lookup during this hang:
>
> ;<<>>  DiG 9.8.3-P1<<>>  cdn.macrumors.com
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43978
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;cdn.macrumors.com.             IN      A
>
> ;; ANSWER SECTION:
> cdn.macrumors.com.      443     IN      CNAME
> mrimages.macrumorscomllc.netdna-cdn.com.
> mrimages.macrumorscomllc.netdna-cdn.com. 143 IN A 108.161.188.3
>
> ---
>
> If I force a page reload on the client, the page loads fine. I'm not
> sure if this is a client and/or browser problem or a dnsmasq setting
> that I'm missing.
>
> Anyone else had/have this problem?
>


You seem to be getting the right answer when you do the query "by hand".

A useful way to debug this is to use the dnsmasq --log-queries option: 
that gives you a log of exactly what happens when the query fails.


Cheers,

Simon.