What Is Authoritative and Non-Authoritative DNS Server?
The Domain Name System (DNS) is a crucial component of the internet infrastructure that translates human-readable domain names into machine-readable IP addresses. DNS servers play a vital role in this translation process by storing and providing access to the mapping information.
Authoritative DNS Server
An authoritative DNS server is a server that contains the original and up-to-date records for a specific domain. It is responsible for providing answers to DNS queries regarding that domain. When a user or another DNS server requests information about a domain, an authoritative DNS server responds with the correct answer.
How Does It Work?
When you register a new domain or make changes to your existing domain’s settings, such as updating the IP address of your website, these changes are made in the authoritative DNS server for your domain. This ensures that anyone accessing your domain receives the most accurate information.
An authoritative DNS server typically stores various types of records, including:
- A Records: These records map a hostname to an IP address.
- CNAME Records: These records create an alias for one hostname to refer to another hostname.
- MX Records: These records specify which mail servers are responsible for accepting email on behalf of a domain.
- TXT Records: These records store arbitrary text data associated with a domain, often used for verification purposes or adding additional information.
Non-Authoritative DNS Server
A non-authoritative DNS server refers to any other DNS server that does not directly contain the original and up-to-date records for a specific domain. Instead, it relies on other DNS servers to provide the requested information.
How Does It Work?
When a non-authoritative DNS server receives a query for a domain it does not have the information for, it forwards the request to another DNS server that is authoritative for that domain. This process continues until the request reaches an authoritative DNS server that can provide the answer.
Non-authoritative DNS servers are commonly used by internet service providers (ISPs) and local networks to cache DNS records. Caching helps reduce network traffic and speeds up subsequent requests for the same domain by storing recently accessed records.
In summary, authoritative DNS servers are responsible for holding and providing accurate information about a specific domain, while non-authoritative DNS servers act as intermediaries, forwarding queries to authoritative servers and caching frequently accessed records.
Understanding the difference between these two types of DNS servers is essential for managing and troubleshooting issues related to domain name resolution.