Setting SOA Parameters for Several DNS Servers

You can set the parameters of SOA records for several DNS server on the Set SOA Parameters page. To edit the SOA record(s) of certain DNS server(s), check them in the list on the Centralized DNS page and click Set SOA Parameters.

Note: If the DNS server is configured to run in Slave mode, it uses the SOA parameters of the Master DNS server is it assigned to. The parameters you set on this page for a Slave DNS server will be ignored.

On the SOA Settings page

1. Set the following parameters of SOA records:

Parameter Name	Description	Notes
E-mail	the mailbox of the person responsible for this DNS server.
TTL	"time-to-live": the time, in seconds, this DNS server caches (keeps) a piece of information received from your server before it asks your server again.	If you set the value too low, your server will get loaded down with too many repeat requests. If you set it too high, the information you change will not get distributed in a reasonable amount of time. By default, 86400 seconds (1 day) is set. The solution is as follows: If particular information is not expected to change in the near future, one can have a high TTL (anywhere between a day (86400 seconds) and a week (604800 seconds) If information is known to change soon, it can be transmitted with a low TTL (an hour to a day). It is standard practice to reduce the TTL transmitted with information that is scheduled to change in order to make that change visible rapidly throughout the Internet; once the change has happened, the TTL is increased again.
Refresh	the time interval, in seconds, before which the zones need to be updated.	By default, 10800 (3 hours) is set. A good value here would be 3600 (1 hour).
Retry	the time interval, in seconds, after which the next attemp of refresh should be taken, after a refresh failure.	By default, 3600 (1 hour) is set. A good value here would be 600 (10 minutes).
Expire	the upper limit, in seconds, on the time interval that can elapse before the zones are no longer authoritative	By default, 604800 (7 days) is set. A nice value here would be 3600000 (42 days).
Minimum TTL	the minimum number of seconds to be used for TTL value in RRs.	By default, 86400 (1 day) is set, which is a good value.

2. Click OK to apply the changes.