DNS client definition
A DNS client, also called a stub resolver, is a service that resolves domain names, such as nordvpn.com, into IP addresses, such as 192.0.2.1, using an external DNS server. It runs on computers and devices to translate human-readable domain names into the numeric IP addresses needed for network communication.
When you access a website, the DNS client sends a query to a DNS resolver (recursive DNS server) requesting the IP address for that domain. The resolver responds with the corresponding IP address, allowing your device to connect to the destination. To improve speed, the DNS client caches previously resolved addresses locally. If the requested information isn't cached, it queries the appropriate remote DNS server.
DNS clients are essential for accessing hosts with dynamic IP addresses that change each time they connect to the internet. The DNS client automatically retrieves the updated IP address, ensuring uninterrupted connectivity.
See also: DNS query, dynamic IP, DNS resolution, DNS cache, DNS proxy, dynamic DNS, authoritative DNS server, DNS over HTTPS, DNS failover
How DNS clients work
- Client sends DNS query. A user enters a domain name, and the DNS client sends a request to resolve it into an IP address.
- DNS server checks configuration. The DNS server looks up the domain and finds multiple IP addresses configured for the same hostname in its records.
- Server rotates IP addresses. The DNS server returns one of the IP addresses in a rotating sequence, ensuring each new query receives a different IP from the list.
- Client receives an IP address. The client gets the assigned IP address from the current position in the rotation cycle.
- Connection established to server. The client uses this IP address to connect to one of the multiple servers hosting the service.
- Result stored temporarily. The IP address is cached locally for a short period (based on TTL), so immediate repeat requests go to the same server before the next rotation occurs.
Importance of DNS clients
- Simplifies internet navigation. DNS clients eliminate the need to memorize complex IP addresses. Instead of typing "192.0.2.1," you simply enter "example.com," making the internet accessible and user-friendly for everyone.
- Provides network transparency. DNS clients work behind the scenes to handle all name resolution automatically. Users don't need to understand the technical process — they just type a domain name and connect seamlessly.
- Enables efficient communication. By quickly translating domain names to IP addresses, DNS clients facilitate fast connections between devices and servers, ensuring smooth data exchange across networks and applications.
- Improves security and privacy. Modern DNS clients can use encrypted DNS protocols (like DNS-over-HTTPS or DNS-over-TLS) to protect queries from interception, preventing third parties from monitoring your browsing activity.
- Reduces network latency and improves performance. DNS clients cache previously resolved domain names locally, eliminating the need to query remote servers repeatedly. This speeds up website loading times and reduces unnecessary network traffic.
