Implementing the Secondary DNS zone is a great choice to keep a reliable copy of your data. Let’s make things a little bit more clear and explain more about it.
DNS zone explained.
The DNS server is capable of holding a lot of zones to manage the DNS namespace more accurately. As a piece of that namespace is the DNS zone. It is a section that provides more organized and easy to control DNS components.
In order for your domain to work properly and accurately, you should have to point it to different servers, for example, mail servers, web servers, etc. To complete this task, you have to create multiple DNS records in the DNS zone.
All of your DNS records are going to be stored in the DNS zone. Furthermore, the existence of the Domain Name System is based on that one piece. The reason for this is that every part of it exists in a zone.
A DNS zone can be applicable for .com, example.com, info.example.com. However, if we examine a subdomain as a website on its own, that will need management on its own. This is because the subdomain could require a separate zone.
The DNS zone includes essential information about the DNS records, also contact information about the DNS zone administrator. It also contains zone parameters like Refresh and Retry rate described in the SOA (Start of Authority) record.
What is a Secondary DNS zone?
It is a read-only copy of the DNS records you built in your Primary (Master) DNS zone. It is also named Slave or Backup DNS zone. It is crucial to understand that the DNS records, such as A or AAAA records, MX records, etc., cannot be attached straight to the Secondary DNS zone. The single way for your Backup zone to get the records you have renewed is through the Primary (Master) DNS zone of the DNS server. So if you require to maintain your DNS records in the Backup zone, you can do it just at your master server.
One of the main ideas of a Secondary DNS zone is to assist as a backup. So if your Primary DNS zone is not working for some reason, that is not going to disturb you. This Backup zone will serve and yet respond to requests for the zone from its copy.
DNS zone transfer
It is a simple task to copy the data from the Primary DNS zone to the Secondary DNS zone. This process is also known as DNS zone transfer, which you can complete this task through two types of zone transfer.
- Full zone transfer (AXFR) – This is a full zone transfer. The whole zone file will be copied in the Secondary DNS zone.
- Partial zone transfer (IXFR) – In this situation, the Secondary servers are going first to examine all the latest changes. For example, if there are deleted and added DNS records that appeared after their last update. After that, they are going to get only the new ones.