grammar: oxford comma

[thirdparty/pdns.git] / docs / modes-of-operation.rst

diff --git a/docs/modes-of-operation.rst b/docs/modes-of-operation.rst
index 658b2bfd6563684fb23104ab10059b55e3adb918..bf76cf28e970bf44bc9448f7210daf0247cbf6e2 100644 (file)
--- a/docs/modes-of-operation.rst
+++ b/docs/modes-of-operation.rst
@@ -109,7 +109,12 @@ back on checking the domain for
 :ref:`setting-soa-retry-default` seconds
 between checks. With default settings, this means that PowerDNS will
 back off for 1, then 2, then 3 etc. minutes, to a maximum of 60 minutes
-between checks.
+between checks. The same hold back algorithm is also applied if the zone
+transfer fails due to problems on the master, i.e. if zone transfer is
+not allowed.
+
+Receiving a NOTIFY immediately clears the back off period for the
+respective domain to allow immediately freshness checks for this domain.
 
 .. warning::
   Slave support is OFF by default, turn it on by adding