unbound-config

> Linux pihole2 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux

server:
    # If no logfile is specified, syslog is used
    logfile: "/var/log/unbound/unbound.log"
    verbosity: 2

    port: 5353
    do-ip4: yes
    do-udp: yes
    do-tcp: yes

    # May be set to yes if you have IPv6 connectivity
    do-ip6: no

    # Use this only when you downloaded the list of primary root servers!
    root-hints: "/var/lib/unbound/root.hints"

    # Trust glue only if it is within the servers authority
    harden-glue: yes

    # Require DNSSEC data for trust-anchored zones, if such data is absent, the zone becomes BOGUS
    harden-dnssec-stripped: yes

    # Don't use Capitalization randomization as it known to cause DNSSEC issues sometimes
    # see https://discourse.pi-hole.net/t/unbound-stubby-or-dnscrypt-proxy/9378 for further details
    use-caps-for-id: no

    # Reduce EDNS reassembly buffer size.
    # Suggested by the unbound man page to reduce fragmentation reassembly problems
    edns-buffer-size: 1472

    # Perform prefetching of close to expired message cache entries
    # This only applies to domains that have been frequently queried
    prefetch: yes

    # This attempts to reduce latency by serving the outdated record before
    # updating it instead of the other way around. Alternative is to increase
    # cache-min-ttl to e.g. 3600.
    cache-min-ttl: 0
    serve-expired: yes
    # serve-expired-ttl: 3600 # 0 or not set means unlimited (I think)

    # Use about 2x more for rrset cache, total memory use is about 2-2.5x
    # total cache size. Current setting is way overkill for a small network.
    # Judging from my used cache size you can get away with 8/16 and still
    # have lots of room, but I've got the ram and I'm not using it on anything else.
    # Default is 4m/4m
    msg-cache-size: 128m
    rrset-cache-size: 256m

    # One thread should be sufficient, can be increased on beefy machines.
    num-threads: 2

    # Ensure kernel buffer is large enough to not lose messages in traffic spikes
    so-rcvbuf: 1m

    # Ensure privacy of local IP ranges
    private-address: 192.168.0.0/16
    private-address: 169.254.0.0/16
    private-address: 172.16.0.0/12
    private-address: 10.0.0.0/8
    private-address: fd00::/8
    private-address: fe80::/10

    # Allow this domain, and all its subdomains to contain private addresses.
    private-domain: "lab.example.com"

    # enable remote-control
    remote-control:
    control-enable: yes

# enable extended statistics.  REQUIRES: <https://www.zabbix.com/documentation/3.4/manual/concepts/sender>
server:
    statistics-interval: 0
    extended-statistics: yes
    # set to yes if graphing tool needs it
    statistics-cumulative: yes