Another systemd-resolved problem in 17.04

[Tom H]

On Thu, Jun 22, 2017 at 10:00 AM, Chris Green <cl at isbd.net> wrote:
> On Thu, Jun 22, 2017 at 08:40:45AM -0400, Tom H wrote:
>> On Thu, Jun 22, 2017 at 3:53 AM, Chris Green <cl at isbd.net> wrote:
>>> On Wed, Jun 21, 2017 at 06:07:54PM -0400, Tom H wrote:
>>>>
>>>> resolved is querying the wrong server because "fe80::..." is an ipv6
>>>> link-local address.
>>>>
>>>> Is there a log of when and/or why it became the dns server?
>>>
>>> The systemd-resolved set up on 17.04 has a local to the machine
>>> caching DNS so it could be right. It listens on 127.0.0.53 port 53.
>>>
>>> I don't quite understand why it's using IPV6 though, I thought I'd
>>> told everything not to use IPV6.
>>
>> What I was asking was:
>>
>> Is there a "Switching to DNS server ... fe80..." or "Switching to
>> fallback DNS server ... fe80..." in the log?
>
> Jun 21 09:21:27 t470 systemd-resolved[961]: Transaction 13674 for <sync-445-us-west-2.sync.services.mozilla.com IN A> scope dns on wlp4s0/*.
> Jun 21 09:21:27 t470 systemd-resolved[961]: Using feature level UDP+EDNS0+DO+LARGE for transaction 13674.
> Jun 21 09:21:27 t470 systemd-resolved[961]: Using DNS server 192.168.1.2 for transaction 13674.
> Jun 21 09:21:27 t470 systemd-resolved[961]: Sending query packet with id 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Timeout reached on transaction 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Retrying transaction 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Switching to DNS server fe80::1e74:dff:fe9d:5b1c%3 for interface wl p4s0.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Cache miss for sync-445-us-west-2.sync.services.mozilla.com IN A
> Jun 21 09:21:28 t470 systemd-resolved[961]: Transaction 13674 for <sync-445-us-west-2.sync.services.mozilla.com IN A> scope dns on wlp4s0/*.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Using feature level UDP for transaction 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Using DNS server fe80::1e74:dff:fe9d:5b1c%3 for transaction 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Sending query packet with id 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Processing incoming packet on transaction 13674.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Transaction 13674 for <sync-445-us-west-2.sync.services.mozilla.com IN A> on scope dns on wlp4s0/* now complete with <rcode-failure> from network (unsigned).
> Jun 21 09:21:28 t470 systemd-resolved[961]: Freeing transaction 41827.
> Jun 21 09:21:28 t470 systemd-resolved[961]: Sent message type=error sender=n/a destination=:1.26631 object=n/a interface=n/a member=n/a cookie=106057 reply_cookie=2 error=Could not resolve 'sync-445-us-west-2.sync.services .mozilla.com', server or network returned error REFUSED
> Jun 21 09:21:28 t470 systemd-resolved[961]: Sent message type=method_call sender=n/a destination=org.freedeskto p.DBus object=/org/freedesktop/DBus interface=org.freedesktop.DBus member=RemoveMatch cookie=106058 reply_cooki e=0 error=n/a
> Jun 21 09:21:28 t470 systemd-resolved[961]: Got message type=method_return sender=org.freedesktop.DBus destinat ion=:1.22 object=n/a interface=n/a member=n/a cookie=79941 reply_cookie=106058 error=n/a
> Jun 21 09:21:28 t470 systemd-resolved[961]: Freeing transaction 13674.
>
> ... but why is it switching to a backup DNS server that I haven't specified anywhere? Not to mention why is
> is it timing out, 192.168.1.2 is a system on the LAN with nothing else to do except DNS

I have no idea why 192.168.1.2 is failing (didn't you have failures in
another thread?) or why resolved is switching to "fe80..." :(

Is there any config in

/etc/systemd/resolved.conf
/etc/systemd/resolved.conf.d/*.conf
/lib/systemd/resolved.conf.d/*.conf
/run/systemd/resolved.conf.d/*.conf

that sets "fe80..." as the DNS server?