DNSonly

DNSonly (often written DNSOnly or DNS-Only) is a term used to describe a system that provides Domain Name System services exclusively, with other network services either disabled or handled by separate devices. In a DNS-only deployment, the primary role of the machine is to resolve domain names, host authoritative zone data, or both, rather than providing DHCP, VPN, firewall, or NAT functions.

DNS services in a DNS-only setup can take different forms. A recursive resolver answers client queries by traversing the DNS hierarchy and may offer caching to improve speed and reduce upstream traffic. An authoritative server hosts and responds to queries for specific zones, ensuring that domain data is available to the Internet or an internal network. Some deployments combine both responsibilities, acting as a recursive resolver for a local network while serving selected authoritative zones.

Common software used for DNS-only configurations includes widely adopted DNS servers such as BIND, Unbound, Knot DNS, and PowerDNS, as well as lightweight options like dnsmasq. These can run on various platforms, including Linux, BSD, and other operating systems, and are frequently deployed on dedicated hardware, virtual machines, or within network appliances. Modern DNS-only setups may support advanced features such as DNSSEC validation, DNS-over-TLS or DNS-over-HTTPS transport, and extensive logging and monitoring.

Typical use cases include home networks seeking centralized, efficient name resolution; small to medium enterprises aiming to reduce external DNS latency; and environments requiring strict separation of DNS from other services for security or management reasons. Operational considerations include ensuring redundancy, keeping software up to date, implementing access controls, and coordinating with upstream providers for reliability and security.