NSD

NSD stands for Name Server Daemon, and it was created as a lightweight, authoritative only alternative to BIND. It does not perform recursive resolution or caching, which makes it ideal for serving authoritative zone data at scale. NSD uses a database driven approach with NSD Control Protocol (NCP) for remote management. It supports DNSSEC signing and validation, AXFR and IXFR zone transfers, and can handle millions of zones efficiently. The software is written in C and runs on Linux, BSD, and other Unix-like systems. NSD is developed by NLnet Labs, the same team behind Unbound (a recursive resolver) and ldns. It is designed for speed and security, featuring a small memory footprint and resilience against certain types of attacks. The tool is configured through a simple text file and zone files, and it includes tools like nsd-checkconf and nsd-notify for administration. Version 4.x is the current stable line, with incremental improvements in performance and DNSSEC handling. NSD is a good fit for operators who want a no frills, fast authoritative server without the overhead of running a full resolver stack. It is also commonly used in combination with Unbound for a split DNS architecture.