A DNS server is a program or device which is dedicated to providing services to the DNS “clients.” The clients are the other programs which usually include web browsers.
All devices connected to the internet have an in-built DNS client. This includes desktops and mobile operating systems.
These devices use the client-server model, which uses a centrally located server to get the required data.
]One of the reasons for using this model is that the servers are typically more reliable and powerful than mobile devices.
Configuring the DNS servers into different architectures can assist organizations in defending their network against online security risks. Using protected DNS servers is one of the methods for enhancing security and preventing malware from spreading. Additionally, user data privacy can also be improved using secure DNS servers.
WHAT ARE THE DIFFERENT TYPES OF DNS SERVERS?
The purpose of different types of DNS servers is to complete the name resolution procedure after receiving a query.
The two authoritative servers — the primary server and the secondary server — should both have access to the data for any site.
The main categories of DNS servers are primary servers, secondary servers, caching servers, and forwarding DNS servers.
These servers have different roles and functionalities. Therefore, it is important to understand how the three distinct types of DNS servers cooperate to determine domain names.
The primary server has no more authority over the zones than the secondary server. Both the primary and secondary servers govern the zones they manage. One of their main differences is where they read their zone files.
PRIMARY SERVER
As it is the first point of contact for the client, this server contains the controlling zone file. It is designated as an authoritative server for a zone.
If this server returns the IP address of the requested domain, the query is resolved. It is also involved in adding subdomains and other administrative tasks.
These tasks include providing all zone file revisions, additions, and changes that must be made.
SECONDARY SERVERS
This type of server serves as the standby of the primary DNS server. If the primary server is unavailable due to hardware malfunction, cyberattack, or power outage, these DNS queries are sent to the secondary servers.
Having a secondary server is highly recommended for this reason. The primary server transfers control to the secondary server while sending data.
CACHING SERVERS
This type of server only provides services to the cached queries for DNS responses. They can respond to clients’ repeated queries. DNS caching can be done at the Operating System and Browser DNS levels.
The amount of time for which the data is stored in the servers is crucial because it determines how fresh the data is.
This time is referred to as TTL or time to live. When a DNS query reaches a machine, the first match is sought at the operating system level.
If no record is found at this level, the query is forwarded to the Internet Service Provider (ISP).
FORWARDING DNS SERVER
This type of DNS server is involved in DNS forwarding. It is a process in which particular sets of DNS queries are handled by a designated server instead of the initial servers.
This saves the initial servers’ work, thus improving clients’ DNS resolution times. It adds an additional link in the DNS resolution chain by constructing a forwarding server that forwards all requests to another DNS server with recursive abilities.
A forwarding DNS server ensures that private servers handle internal requests while external queries are directed by public DNS.
This is done by conditionally sending requests to other servers. This process of forwarding to separate servers can create intriguing flexibility in separating public and private traffic.
PUBLIC VS. PRIVATE DNS SERVERS
The DNS servers may also be classified as public or private servers based on their accessibility. Private DNS servers handle isolated networks and provide multiple layers of security.
On the other hand, the public DNS server is the nameserver that networked computers in public may use to resolve the DNS query.
The most common example of public DNS is the one provided by your Internet Service Provider. It can be accessible to anyone on the internet.
Private servers are a much safer option than public ones because they are protected by a company firewall and maintain records of internal websites.
Learning more about the types of DNS servers is important for better network security.
CONCLUSION
Having an understanding of the DNS servers is essential for networking and online safety. It can help you select the one that will be most useful for your business requirements.
Moreover, you can also modify your own DNS for greater performance and security, which adds to the granularity of your cybersecurity system.