What is the “TTL” parameter used for (Time To Live).

If you choose to use the Name Servers of Aruba, in the page relevant to the Name Server Record you can also set the TTL parameter (Time To Live).



 
The Time To Live indicates the length of time for which the settings of the zone are kept in the cache of the DNS which requested that specific information.

The higher the TTL value will be, the fewer queries will be made to the authoritative DNS: this way you will not weigh the Server down with endless requests.

If a high TTL value is useful seeing that it avoids making continuous queries to the Server, you need to make sure that such parameter is set to the lowest value if you wish to make changes to the DNS.

This value, in fact, by determining the length of time for which the settings are saved in the cache of the DNS, consequently also determines the time needed for the execution of the changes.

It is therefore recommended, if you wish to make changes on the Records that you set the value of the parameter to the minimum, in order to speed up the execution of the changes, then putting it back to the original value once the changes have been completed.

The default value of the TTL, will be 24 hours (1D). Such value can be changed by selecting one of the options found in the drop-down menu next to TTL.

To complete the modifications you will need to click on “Continue” and then on “Save Configuration” in the main page.

ATTENTION: The changes made on the TTL will only be effective once the TTL that was previously set expires.

For example: by switching from a 24 hours TTL, to a 30 minute TTL, all the DNS servers will recognize the new TTL only once the previously set 24 hours have passed, length of time for which the information remains stored in the cache.

Whereas by switching from a 30 minute TTL to a TTL with longer duration, the change will only be detected by the servers after the thirty minutes previously set.