[Dnsmasq-discuss] DNSSEC slow query / TCP/ truncated issue

[Geert Stappers]

On 11-08-2019 22:01, Dominic Preston wrote:

> Hi,
>
> I have a fresh installation of Ubuntu 18.04 on Google Cloud Platform.
> I have compiled the latest version of dnsmasq with the following
> configuration:
>
> no-resolv
> server=8.8.8.8
> conf-file=/usr/share/dnsmasq-base/trust-anchors.conf
> dnssec
>
> I stop systemd-resolved, run dnsmasq and issue the following command:
>
> dig @127.0.0.1 pir.org
>
> After that there's a long pause, and the result comes back with the
> following line at the top of dig:
>
> ;; Truncated, retrying in TCP mode.
>
> dnsmasq log says:
>
> dnsmasq: reducing DNS packet size for nameserver 8.8.8.8 to 1280
>
> If I run this, dig comes back immediately with no pause and no TCP mode:
>
> dig @8.8.8.8 pir.org
>
> Any ideas why the first dig command has problems and the second dig
> command is fine?
>

How to stack[1] systemd-resolved and dnsmasq is something britle.  I
took me several attempts.  None of the attempts had `reducing DNS packet
size`.  Feel free to report your milage.


Regards

Geert Stappers