The following options have been extended or added to the BIND utility version 9.9.4:

* inline-signing
This option can be used in zone Statement. If set to "yes", the unsecured zone, which is either loaded from the disk or transferred, is signed in real time and served as signed.

* request-ixfr
This option can now also be used in a zone block of the configuration. Setting this option overrides the global setting or the view setting for the respective zone.

* serial-update-method
This new option can be used to specify an automatic zone serial number for zones configured for a dynamic DNS (DDNS). The available options are "increment" for incrementing the serial number by one after each zone update, or "unixtime" for setting the serial number to the number of seconds since the UNIX epoch.

* also-notify
This option now has the same syntax as the zone's "master" option. This means it is now possible to specify which transaction signature (TSIG) key to use when sending an update to a remote server or to include an explicit named masters list.

* dnssec-loadkeys-interval
This new option can be used to set the frequency of the checks for new keys if the zone has been configured with the "auto-dnssec maintain;" option. The time is specified in minutes with the default value set to 60 minutes. The minimum value is 1 minute and the maximum is 1440 minutes (24 hours). Any greater value is silently reduced to 1440 minutes.

For more information, see the BIND9 Administrator Reference Manual located in the /usr/share/doc/bind-9.9.4/ directory.