BIND 9.18 does not support sending forwarded DDNS update requests
through DoT.
observers but does not protect from man-in-the-middle attacks on
zone transfers.
+.. warning::
+
+ Please note that this version of BIND 9 does not support dynamic updates
+ forwarding (see :any:`allow-update-forwarding`) in conjuction with zone
+ transfers over TLS (XoT), that is when the :any:`tls` keyword is used with
+ :any:`primaries`, e.g. ``primaries { 192.0.2.1 tls tls-configuration-name; };``.
+
.. _options_grammar:
``options`` Block Grammar