docs: clarify settings for allow-dnsupdate-from

diff --git a/docs/settings.rst b/docs/settings.rst
index f67f185c2df994ee055400970e4e0e16ee0f660a..c4c92d4c103d6c92536be62035b3b1beaaad870f 100644 (file)
--- a/docs/settings.rst
+++ b/docs/settings.rst
@@ -43,8 +43,9 @@ AXFR.
 ------------------------
 
 -  IP ranges, separated by commas
+-  Default: 127.0.0.0/8,::1
 
-Allow DNS updates from these IP ranges.
+Allow DNS updates from these IP ranges. Set to empty string to honour ``ALLOW-DNSUPDATE-FROM`` in ``domainmetadata``.
 
 .. _setting-allow-notify-from: