Ubuntu 18.04: unbound seems to stop working after a period of time

[Jakob Habedank]

It is weird to me. dig is getting timeouts on the host machine but logs
don't show anything after specific time:

    journalctl -f -u unbound
    -- Logs begin at Sat 2019-08-17 16:52:42 CEST. --
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: prime
trust anchor
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: resolving
. DNSKEY IN
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: validate
keys with anchor(DS): sec_status_secure
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info:
Successfully primed trust anchor . DNSKEY IN
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: resolving
_ta-4a5c-4f66. NULL IN
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info:
validate(positive): sec_status_secure
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info:
validation success . DNSKEY IN
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: response
for _ta-4a5c-4f66. NULL IN
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: reply
from <.> 192.33.4.12#53
    Aug 23 06:28:26 homeserver unbound[21476]: [21476:0] info: query
response was NXDOMAIN ANSWER

Moreover systemctl is reporting that unbound is still running. Is there
something else I could try?

Am 21.08.19 um 22:00 schrieb Jakob Habedank via Unbound-users:
> Hi all,
>
> I set up pi-hole with unbound on my ubuntu 18.04 machine. I followed the
> instructions by pi-hole[1].
>
> Clients can reach websites with this method but after some time I get
> timeouts. Pihole is still forwarding requests to 127.0.0.1 but it seems
> that unbound doesn't answer anymore. Even on the host machine I get
> timeouts.
>
>     dig pi-hole.net @127.0.0.1 -p 5353
>
>     ; <<>> DiG 9.11.3-1ubuntu1.8-Ubuntu <<>> pi-hole.net @127.0.0.1 -p 5353
>     ;; global options: +cmd
>     ;; connection timed out; no servers could be reached
>
> Only `systemctl restart unbound` solves this problem. Unbound is still
> running and doesn't show any obvious errors though.
> I posted on the pi-hole forums and added quite some information there so
> you might want to check the thread [2].
>
> I'm quite new to Unix so please tell me what information you need to
> help. Thanks!
>
> [1] https://docs.pi-hole.net/guides/unbound/
>
> [2]
> https://discourse.pi-hole.net/t/pihole-on-ubuntu-18-04-with-unbound-fails-after-some-time/22585
>
>