The NLnet Labs Name Server Daemon (NSD) is an authoritative DNS name server. It has been developed for operations in environments where speed, reliability, stability, and security are of high importance. It is distributed free of charge in open source form under the BSD license. For most platforms, packages are available and the latest version of NSD can always be downloaded from the NLnet Labs website

NSD has a pure design philosophy that prioritises raw performance. This means that if you serve hundreds of thousands or even millions of queries per second, NSD is the leading implementation in the world according to independent benchmarks. This makes the name server ideally suited for Top Level Domain implementations, DNS Root servers and anyone in need of a fast and optimised authoritative name server. Currently, three DNS root servers and many top-level domain registries use NSD as part of their server implementation. NSD has not implemented recursive caching by design. If you need a validating, recursive, caching resolver then NLnet Labs has Unbound available.

NSD strives to be a reference implementation for emerging standards in the Internet Engineering Task Force (IETF). The aim is to implement well-established Internet Drafts as a compile option and drafts in the final stage of open community review as an optional feature, that is disabled by default. Accepted RFCs are implemented in NSD according to the described standard. 

NSD is covered by a security patch policy. If you run NSD in a mission critical environment and you would like support backed by a Service Level Agreement directly from the developers at NLnet Labs, please visit our support page for more information.