Today the focus of our article is exactly DNS zone transfer. Is it something you’ve heard about? If not, no worries. In a moment, we’ll discover what it is and why understanding it is critical. So let’s not waste time and get started.
What is a DNS zone?
The DNS zone is a tiny part of the Domain Name System (DNS). However, despite its size, it serves an essential purpose: it allows various DNS administrators to control and manage multiple aspects of the global DNS system. That is the primary reason for the decentralized nature of this global naming database.
The DNS zone contains a collection of DNS records such as A, AAAA, MX, TXT, PTR, etc. It’s worth noting that the SOA record, which is the initial DNS record, also contains basic information about the zone, the DNS administrator, and some parameters (Refresh and Retry rate) that are required for DNS zone transfer.
DNS zone transfer – definition
The process of replicating DNS information (DNS records) from the Primary DNS zone to the Secondary DNS zone is known as zone transfer. This allows you to set up numerous copies of your DNS records on different name servers. As a result of completing the transfer, you will have higher availability if one of the name servers fails. Furthermore, if you own an international website with users from all over the world and different presence places, you will ensure faster DNS resolution (PoPs).
Another critical point to remember is that your website will not be harmed if a particular name server is down for whatever reason (for example, maintenance or a DDoS attack). For your guests, it will remain available and reachable.
If you manage a website with a global presence and wish to increase DNS resolution speed, you might consider completing a zone transfer to many Secondary DNS zones. You’ll be able to put your DNS data (DNS records) in multiple Points of Presence(PoP) in this manner.
Types of DNS zone transfer
Generally, there are two different types of DNS zone transfers between name servers that you can perform :
- Transfer of the entire zone (AXFR zone transfer). This one is for copying all DNS records from the primary name server to a secondary name server (Secondary). If you haven’t updated the Secondary in a while and want to make sure it’s up to date, you can utilize it. Another reason to do the entire zone transfer is to copy data to a newly deployed name server with no previous information.
- Partial zone transfer (IXFR zone transfer). We use it to update only the newly modified DNS records from the Primary name server to the Secondary name servers (removed, changed, or generated). You can use it to save bandwidth by simply updating changes. This isn’t the entire zone file. It’s more convenient to utilize after you’ve set up all of the secondary name servers.
In conclusion, we can say that you are familiar with the fundamental DNS zone transfer. It’s the process that allows DNS data replication to be quick and straightforward. However, without a good knowledge of what it is, you won’t be able to deploy it successfully.