Updating the transfer rule
By default BIND9 will send NOTIFY messages to all the target names (right-hand names) that appear in NS RRs for the zone (this behaviour can be modified by the notify statement.Note: The also-notify statement can appear in a zone file, in which case its scope is the single zone, or in an options clause, in which case its scope is all zones, or in a view clause, in which case it applies to all zones in the view.These IP(s)s are in addition to those listed in the NS records for the zone.The also-notify in a zone is not cumulative with any global also-notify statements.// fragment // key clause is shown only for illustration and would // normally be included in the file key "update-key" ; .... zone "example.com" in; zone "example.org" in; In the zone, the reference to the key clause "update-key" implies that the application that performs the update, say nsupdate, is using TSIG and must also have the same shared secret with the same key-name.This statement may be used in a zone, view or an options clause.This statement may be used in a zone, view or global options clause.
This address must appear in the remote end's allow-transfer statement for the zone being transferred.
If a global notify statement is 'no' this statement may be used to override it for a specific zone and, conversely, if the global options contain a also-notify list, setting notify 'no' in the zone will override the global option.
This statement may be used in normal zone, view or a global options clause.
If set to yes when the server receives a new version of a slave file by a non-incremental zone transfer it will compare the new version to the previous one and calculate a set of differences.
The differences are then logged in the zone's journal file (appended to zone file name) such that the changes can be transmitted to downstream slaves as an incremental zone transfer.
The format of also-notify changed in BIND9.9 to that shown below. The also-notify statement is relevant only with master zones and defines one or more IP addresses, and optional port numbers, of servers that will be sent a NOTIFY when the master zone file is reloaded.