unbound: prefer ip4 on ubuntu 24 and above

ip6 queries seems to be blocked by spamhaus

setup/start/unbound/prefer-ip4.conf

@@ -0,0 +1,6 @@
+# Prefer IPv4 outbound queries. Spamhaus often reject queries from IPv6 addresses
+# This setting is in a separate file since it only works from Ubuntu 24 , unbound 1.19.2
+
+server:
+    prefer-ip4: yes
+

setup/start/unbound/unbound.conf

@@ -0,0 +1,22 @@
+# Unbound is used primarily for RBL queries (host 2.0.0.127.zen.spamhaus.org)
+# We cannot use dnsmasq because it is not a recursive resolver and defaults to the value in the interfaces file (which is Google DNS!)
+
+server:
+        port: 53
+        interface: 127.0.0.150
+        interface: 172.18.0.1
+        ip-freebind: yes
+        do-ip6: yes
+        prefer-ip4: yes
+        access-control: 127.0.0.1 allow
+        access-control: 172.18.0.1/16 allow
+        cache-max-negative-ttl: 30
+        cache-max-ttl: 300
+        # enable below for logging to journalctl -u unbound
+        # verbosity: 5
+        # log-queries: yes
+
+# https://github.com/NLnetLabs/unbound/issues/806
+remote-control:
+    control-enable: no
+