A master nameserver (also called native, primary or authorative) manages the zone file locally, on that specific machine. A change in this zone file will be visible in the DNS zone immediately. DNS zones can only be changed on a master nameserver (also refer to the information about Slave in this article).
A nameserver is the address label for a domain name. The nameserver translates the human readable domain name or host name, to a computer readable IP address. This makes it easier to visit websites, you can type in www.openprovider.nl instead of 18.104.22.168 in your browser.
Mail (MX) records can be assigned a priority in a DNS zone. When an e-mail should be delivered, this is tried first on the mail server with the lowest value for priority. When that mail server cannot be reached, the mail server with the next lowest value for priority will be tried, etcetera. Mail servers that have equal priority are chosen randomly.
Make sure your most important mail server has the lowest value for priority; a mail server that functions only as back-up, might get a higher value.
A DNS zone is built of a collection of records, that each assign a address to a specific service. For example, there are records that define mail server, and records that define subdomains. An overview of all record types can be found further in this FAQ ().
A slave nameserver (also called secondary) doesn't get its data from a local zone file like a master nameserver, but fetches its data periodically from the assigned master nameserver. This means that the master nameserver should have the domain configured, but also that the master nameserver might be read out by the slave nameserver. The only task a slave nameserver performs, is copying data from the zone file of the master nameserver. In case the master nameserver cannot be read any more, the slave will be inactive after expiration of the TTL's.
It is not possible to change records of a slave zone; in case records should be changed, this should be done in the master nameserver. The slave nameserver will copy the new data automatically.
The Time To Live (TTL) of a record defines how long the record may be stored in the cache of the ISP. This prevents the nameserver from being queried each time the domain is visited. Only after the expiration of the TTL, the nameserver will be queried again, to catch a possible changed value. By default, the TTL in Openprovider is 1 day. This means that, when you 'now' query a domain from a nameserver, and immediately afterwards change one of the records, this change will be visible only after 24 hours.
It is possible to lower the TTL, for example when preparing a migration to another server. To minimize inconvenience, you can lower the TTL to, for example, one hour. This means that all users will have access to the new data within 1 hour.
A DNS zone is the collection of DNS records that belong to a domain.