A pretty good unbound.conf, DNSSEC, caching and local forwarding

unbound.conf

remote-control:
  control-enable: yes
server:
  do-ip6: no
  do-ip4: yes
  do-udp: yes
  tls-cert-bundle: /etc/ssl/certs/ca-certificates.crt
  num-threads: 4
  # Enable logs
  verbosity: 1
  # List of Root DNS Server
  root-hints: "/var/lib/unbound/root.hints"
  # Use the root servers key for DNSSEC
  auto-trust-anchor-file: "/var/lib/unbound/root.key"
  # Respond to DNS requests on all interfaces
  interface: 0.0.0.0
  max-udp-size: 3072
  # Authorized IPs to access the DNS Server
  access-control: 0.0.0.0/0                 refuse
  access-control: 127.0.0.1                 allow
  access-control: 10.42.0.0/16              allow
  # not allowed to be returned for public internet  names
  private-address: 10.42.0.0/16
  # Hide DNS Server info
  hide-identity: yes
  hide-version: yes
  # Limit DNS Fraud and use DNSSEC
  harden-glue: yes
  harden-dnssec-stripped: yes
  harden-referral-path: yes
  use-caps-for-id: yes
  # Add an unwanted reply threshold to clean the cache and avoid when possible a DNS Poisoning
  unwanted-reply-threshold: 10000000
  # Have the validator print validation failures to the log.
  val-log-level: 1
  # Minimum lifetime of cache entries in seconds
  cache-min-ttl: 300
  # Maximum lifetime of cached entries
  cache-max-ttl: 14400
  prefetch: yes
  prefetch-key: yes
  # Optimisations
  msg-cache-slabs: 8
  rrset-cache-slabs: 8
  infra-cache-slabs: 8
  key-cache-slabs: 8
  # increase memory size of the cache
  rrset-cache-size: 256m
  msg-cache-size: 128m
  # increase buffer size so that no messages are lost in traffic spikes
  so-rcvbuf: 1m
  # Enable unvalidated lookups to VPC internal domains
  private-domain: "internal"
  domain-insecure: "internal"
  unblock-lan-zones: yes
  insecure-lan-zones: yes

forward-zone:
  name: "internal."
  forward-tls-upstream: no
  forward-addr: 10.42.0.2
forward-zone:
  name: "10.in-addr.arpa."
  forward-addr: 10.42.0.2
# All other queries go to trusted DNS providers
forward-zone:
  name: "."
  forward-tls-upstream: yes
  # Quad9
  forward-addr: 9.9.9.9@853#dns.quad9.net
  forward-addr: 149.112.112.112@853#dns.quad9.net
  # Cloudflare DNS
  forward-addr: 1.1.1.1@853#cloudflare-dns.com
  forward-addr: 1.0.0.1@853#cloudflare-dns.com