unbound without internet

[tito]

On Tue, 5 Sep 2023 07:46:53 +0200 (CEST)
Hans Sandsdalen via Unbound-users <unbound-users at lists.nlnetlabs.nl> wrote:

> Hi 
> 
> Yesteday we lost connection to internet. I supposed that dns would be ok for our internal hosts. But unbound became very slow, sometimes did not respond at all. We use nsd and unbound. 
> 
> What can I do to prevent this in the future? 
> 
> /etc/unbound/unbound.conf.d/ contains tree files: 
> KSPT.conf qname-minimisation.conf root-auto-trust-anchor-file.conf 
> 
> KSPT.conf: 
> 
> server: 
> verbosity: 1 
> interface: 0.0.0.0 
> access-control: 192.168.0.0/16 allow 
> access-control: 10.0.0.0/8 allow 
> access-control: 127.0.0.0/8 allow 
> port: 53 
> do-ip4: yes 
> do-ip6: no 
> root-hints: "/etc/unbound/root.hints" 
> cache-min-ttl: 300 
> cache-max-ttl: 86400 
> prefetch: yes 
> num-threads: 1 
> minimal-responses: yes 
> prefetch: no 
> do-not-query-localhost: no 
> local-zone: "domain.no" nodefault 
> local-zone: "168.192.in-addr.arpa" nodefault 
> local-zone: "10.in-addr.arpa" nodefault 
> domain-insecure: "domain.no" 
> domain-insecure: "168.192.in-addr.arpa" 
> domain-insecure: "10.in-addr.arpa" 
> private-domain: "domain.no" 
> stub-zone: 
> name: "168.192.in-addr.arpa." 
> stub-addr: 127.0.0.1 at 1053 
> stub-zone: 
> name: "10.in-addr.arpa." 
> stub-addr: 127.0.0.1 at 1053 
> stub-zone: 
> name: "spacetec.no" 
> stub-addr: 127.0.0.1 at 1053 
> 
> remote-control: 
> control-enable: yes 
> 
> qname-minimisation.conf: 
> 
> server: 
> # Send minimum amount of information to upstream servers to enhance 
> # privacy. Only sends minimum required labels of the QNAME and sets 
> # QTYPE to NS when possible. 
> 
> # See RFC 7816 "DNS Query Name Minimisation to Improve Privacy" for 
> # details. 
> 
> qname-minimisation: yes 
> 
> root-auto-trust-anchor-file.conf: 
> 
> server: 
> # The following line will configure unbound to perform cryptographic 
> # DNSSEC validation using the root trust anchor. 
> auto-trust-anchor-file: "/var/lib/unbound/root.key" 
> 
> --- 
> HANS SANDSDALEN 
> Manager IT Tromsø 
> Space Ground Systems 
> Kongsberg Defence & Aerospace AS 
> 
> +47 977 62 632 
> [ mailto:hans at spacetec.no | hans at spacetec.no ] 
> [ http://www.kongsberg.com/space | www.kongsberg.com/space ] 
> 
> 
> 
> 
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> 
Hi,

    infra-keep-probing: <yes or no>
              If  enabled  the  server keeps probing hosts that are down, in the one probe at a time regime.  Default is no. 
              Hosts that are down, eg. they did not respond during the one probe at a time period, are marked as down
              and it may take infra-host-ttl time to get probed again.

This fixed it for me. Hope this helps.

Ciao,
Tito