Understanding the DNS Server Selection Process for Your Computer

When a computer connects to a network, one of the critical steps is to assign an IP address, including information about the gateway address and DNS server addresses. This process can be manual or automatic, depending on the network configuration.

Network Configuration

The DNS server settings in a computer's network settings are usually configured manually or automatically via DHCP (Dynamic Host Configuration Protocol). If you're using DHCP, the router or DHCP server on the network provides the DNS server addresses to the computer when it connects to the network.

Local DNS Cache

Before querying a DNS server for a domain name resolution, the computer first checks its local DNS cache to see if it has recently resolved the domain name. This cache helps to reduce the number of DNS queries sent to the server, improving efficiency.

DNS Query Process

If the local cache does not contain the IP address, the computer sends a DNS query to the configured DNS server. This query could be directed to a local DNS server provided by your Internet Service Provider (ISP) or a public DNS server such as Google's 8.8.8.8 or Cloudflare's 1.1.1.1.

DNS Resolver

The DNS server that receives the query is known as a resolver. If it doesn't have the answer cached, it performs a series of recursive queries to locate the authoritative DNS servers for the domain in question. This process involves querying root servers, then Top-Level Domain (TLD) servers, and finally the authoritative name servers for the specific domain.

Routing the Information

Once the resolver locates the IP address, it returns it to the original computer, which can then use it to establish a connection to the desired server. This process ensures that your computer can efficiently and accurately resolve domain names to IP addresses.

Managing DNS Settings

Users can manage the DNS settings in their operating system or router settings if they want to use different DNS servers for performance or privacy reasons. This flexibility allows users to choose DNS providers that meet their specific needs.

In summary: A computer knows which DNS server to use based on its network configuration, which can be set up automatically or manually. Users can also change these settings as needed to meet their specific requirements.