auth doc: Document 2-step process for consumer zone updates.

Closes #12714.

diff --git a/docs/catalog.rst b/docs/catalog.rst
index e0ffbdabb776cc5cf37f752b13b602913d748d70..654270a4f766fc7ceab6a5b81f36b454dec55a69 100644 (file)
--- a/docs/catalog.rst
+++ b/docs/catalog.rst
@@ -139,3 +139,19 @@ The only difference is the type, which is now set to CONSUMER.
 Creating consumer zones is supported in the :doc:`API <http-api/zone>`, using type ``CONSUMER``.
 
 New member zones on the consumer adopt their primaries from the consumer zone.
+
+Updating a secondary server when primary address/port changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If NOTIFY+AXFR are being used to replicate zone changes between the
+primary and secondary servers, and the address and/or port of the
+primary server changes, two steps are necessary on each secondary
+server in order to fully apply the changes.
+
+.. code-block:: shell
+
+  pdnsutil change-secondary-zone-primary catalog.example 192.0.2.45
+  pdns_control retrieve catalog.example
+
+This will update the primary server contact details in each zone
+included in the catalog zone.