# Unbound config file
server:
# If no logfile is specified, syslog is used
#logfile: "/var/log/unbound/unbound.log"
verbosity: 3

interface: 127.0.0.1
interface: 186.64.123.31
port: 53
do-ip4: yes
do-udp: yes
do-tcp: yes

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

# You want to leave this to no unless you have *native* IPv6. With 6to4 and
# Terredo tunnels your web browser should favor IPv4 for the same reasons
prefer-ip6: no

# Use this only when you downloaded the list of primary root servers!
# If you use the default dns-root-data package, unbound will find it automatically
root-hints: "/etc/unbound/root.hints"

# Trust glue only if it is within the server's authority
harden-glue: yes

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

trust-anchor-file: "/etc/unbound/trusted-key.key"

# 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.
# IP fragmentation is unreliable on the Internet today, and can cause
# transmission failures when large DNS messages are sent via UDP. Even
# when fragmentation does work, it may not be secure; it is theoretically
# possible to spoof parts of a fragmented DNS message, without easy
# detection at the receiving end. Recently, there was an excellent study
# >>> Defragmenting DNS - Determining the optimal maximum UDP response size for DNS <<<
# by Axel Koolhaas, and Tjeerd Slokker (https://indico.dns-oarc.net/event/36/contributions/776/)
# in collaboration with NLnet Labs explored DNS using real world data from the
# the RIPE Atlas probes and the researchers suggested different values for
# IPv4 and IPv6 and in different scenarios. They advise that servers should
# be configured to limit DNS messages sent over UDP to a size that will not
# trigger fragmentation on typical network links. DNS servers can switch
# from UDP to TCP when a DNS response is too big to fit in this limited
# buffer size. This value has also been suggested in DNS Flag Day 2020.
edns-buffer-size: 1232

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

# One thread should be sufficient, can be increased on beefy machines. In reality for most users running on small networks or on a single machine, it should be unnecessary to seek performance enhancement by increasing num-threads above 1.
num-threads: 1

# 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:0.0.0.0/0
access-control: 0.0.0.0/0 allow

# Hide DNS Server info
#hide-identity: yes
#hide-version: yes

# Add an unwanted reply threshold to clean the cache and avoid, when possible, DNS poisoning
#unwanted-reply-threshold: 10000000

# 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

# Perform prefetching of close to expired message cache entries
# This only applies to domains that have been frequently queried
#prefetch: yes
# Fetch the DNSKEYs earlier in the validation process, which lowers the latency of requests
# but also uses a little more CPU
#prefetch-key: yes