Dns slave server not updating
The crucial difference is where the server gets its data.
not much experience with Ubuntu first IT job in 1990 was a Unix shop but that was only for 3 years and I really hadn't touched it much other than to toy around with it since then. You have to tell BIND to refresh its configuration after you make the changes.
allow-update defines an address_match_list of hosts that are allowed to submit dynamic updates for master zones, and thus this statement enables Dynamic DNS.
The default in BIND 9 is to disallow updates from all hosts, that is, DDNS is disabled by default.
BIND sends notifications by default, however it is good practice to enable them explicitly if they are an important part of the configuration.
This can be done for individual zones: The setting for a zone takes precedence, therefore if you use the latter method then you should check that it has not been overridden.
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You can either restart the process as you have done already, or you can tell the server to reload the configuration by issuing the command: No, you only need to do it when you update a zone's records.