SmartDNS is a local recursive DNS resolver and server that manages granular query rules, dual-stack networking, and encrypted gateway proxying. It functions as a DNS traffic filter and DNS64 translator, allowing IPv6-only clients to communicate with IPv4 servers.
The project distinguishes itself through parallel upstream querying, which sends requests to multiple servers simultaneously to return the response with the lowest network latency. It supports DNS server virtualization, enabling the operation of multiple independent server instances on different ports, each with its own configuration and client sets.
The system provides a multi-protocol transport layer supporting encrypted traffic via HTTPS, TLS, and QUIC. It includes a client-specific rule engine that applies distinct resolution and filtering policies based on the MAC or IP address of the requester, alongside suffix-based domain filtering to block advertisements and malicious websites.