Category: Network

Get familiar with DNS zone transfer 

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.

Best Free DNS Resolvers [Top 5]

Today, this article will take a detailed look at free DNS Resolvers. The importance of a Recursive DNS server cannot be overstated. Looking for something on the Internet without it could be frustrating. You can access this content right now owing to the service of a Recursive DNS server! But can we take advantage of it without having to pay? The answer is yes. So let’s get to know one of the best free DNS Resolvers.

DNS Resolver

The DNS Resolver, or also known as Recursive DNS server, is in charge of looking for data required to respond to user queries. In computers, recursion refers to a method for addressing a problem. This indicates that a program or solution will keep repeating itself until it achieves its purpose.

DNS Resolver serves as a link between authoritative DNS servers and end-users. A Recursive DNS server searches for the IP address every time someone writes a domain name. This server returns to the device’s browser that originated the request after determining the correct IP address for the specific domain name. Finally, by connecting to that IP address, the device can access the specified website, which is then loaded.

Free DNS Resolvers

Now you know what the Recursive DNS server is and how it works. So we can take a look at the best free DNS Resolvers:

1. Google 

Google has a Public DNS that is a quick and easy way to replace your ISP’s nameservers. Its Public DNS servers can accomplish fast speeds because they’re located in data centers worldwide. That means when you try to access a website using the IP addresses above, you’ll be sent to the server closest to you.

Master DNS server:

Slave DNS server:

2. Cloudflare 

Cloudflare created to become the “fastest DNS directory on the internet.” It uses a modern, efficient protocol to replace the connection between your device and the Internet. So this guarantees to never track your IP address, transfer your data or use it to target adverts.

Master DNS server:

Slave DNS server:

3. Quad9 

Quad9 is a new DNS provider, having launched in 2016. It has free public DNS servers that protect your smartphone, tablet, computer, and other devices from cyber risks by instantly blocking harmful web pages without collecting your personal information.

Master DNS server:

Slave DNS server:

4. OpenDNS

OpenDNS has a high level of uptime and stability, and millions of people use it. This company provides two free public DNS servers, one of which is specialized in parental controls and includes lots of filtering settings. It is the greatest solution for families with kids because it blocks adult content.

Master DNS server:

Slave DNS server:

5. CleanBrowsing

CleanBrowsing is the last best Free DNS Resolver on our list. A security filter, an adult filter, and a family filter are three free public DNS server options. These are the DNS servers for the security filter, which is the simplest and refreshes every hour to prevent malware and phishing websites.

Master DNS server:

Slave DNS server:


That concludes our list of the best free DNS Resolvers for your devices to get fast and secure online access. Although most of us never change our DNS servers from our ISP, it is a good idea to do so if you value your privacy.

Anycast DNS vs. Unicast DNS – Which one to choose?

Let’s make the comparison Anycast DNS vs. Unicast DNS. Both of them are mechanisms for routing the incoming traffic of a domain name. Yet, they are very different from one another. So, let’s explain a little bit more about Anycast DNS vs. Unicast DNS!

Anycast DNS – What is it?

Anycast DNS is a routing mechanism that implements multiple name servers. Each one of them is placed in a different geographical position. Yet, the entire group of name servers stores the very same IP address, and each of them is able to provide it. That means the DNS information (containing all available DNS records) for your domain name is stored not on one but multiple name servers.

When a user requests your domain, the DNS server, which is closer, is going to answer and provide the needed data. In case a particular server from the group is not operating, the DNS query is going to receive an answer from one of the other available DNS servers. That affects in a positive way aspects like waiting for a response, loading time, and of course, the user experience.

Unicast DNS explained

Unicast DNS is a routing mechanism that uses a single name server. That means the IP address and the entire DNS data of your domain name are held only on a single DNS server. In this situation, the location of the user does not matter. All of the incoming DNS requests are going to receive an answer from this precise name server. So, if the user is initiating the DNS query from a location that is closer to the name server, it is going to get a fast reply. While in situations when the user is in a completely different location away from that server, it is going to require more time for getting a response.

Anycast DNS vs. Unicast DNS

When we are comparing Anycast DNS vs. Unicast DNS, we can use several factors and criteria to help you decide which one is the better option for your needs. 

  • Easy to use – Unicast DNS means one machine and one IP address. Therefore, installing Unicast DNS could be a little bit simpler. However, it is not that difficult to implement Anycast DNS too. For Unicast DNS, you have to maintain just a single server. Configuring a group of servers requires a little bit more effort.
  • Security – In cases when an individual DNS server stores all of your domain name data and gets attacked or crashes, it can lead to some big losses. The accessibility to your domain is going to be extremely affected, which leads to financial and reputation damages. Anycast DNS provides you with a group of servers, and even if one of them goes down, you can rely on others to take care of the incoming DNS requests.
  • Response time – Anycast DNS provides really fast replies and decreases the waiting time. That means your potential clients won’t leave your website. 
  • Target market – In case you are interested in offering your services or products in a local market, then Unicast DNS is your perfect choice. However, if your target market is a multinational, it is going to be best if you consider Anycast DNS.