NSD

NSD (Name Server Daemon) is an open source and freely distributed command-line software written in C and engineered to implement an authoritative only, complete, simple and high performance DNS (Domain Name System) server on Linux kernel-based operating systems.

It is a modern, fast and RFC-compliant name server solution that is very well tested at the NLnet Labs. When comparing NSD with BIND, it was discovered that there are no interoperability issues for the two domain name resolvers.

Command-line options

Being a command-line software, NSD comes with various options, among which we can mention the ability to only listen to IPv4 or IPv6 connections, listen to specific incoming IP addresses and ports, read a custom configuration files instead of the default one, as well as to specify a database to load, the identity when querying for id.server CHAOS TXT, the NSID or log file.

Additionally, it’s possible to specify the number of servers to start, the maximum number of TCP (Transmission Control Protocol) connections per server, the PID file to write, the port to listen to, or the verbosity level, change root to specified folder when the program starts or change effective UID to a specific user.

Getting started with NSD

To install the latest version of NSD on your GNU/Linux operating system, you must download the source archive (tarball) from Softoware or the official website of the project, save it on your computer, extract its contents, and open your favorite terminal emulator application.

In the Linux Terminal app, use the ‘cd’ command to navigate to the location of the extracted archive files and run the ‘./configure && make’ command to optimize and compile the program for a specific hardware architecture (32-bit and 64-bit are supported at this time).

After a successful compilation, you will be able to install NSD system wide, use the ‘make install’ command as root or the ‘sudo make install’ command. To view its usage message, type the ‘nsd --help’ command in the terminal emulator window.

More documentation, as well as a memory consumption test are available at http://www.nlnetlabs.nl/projects/nsd/documentation.html. Additionally, a regression tests report has been made available on the project’s homepage.

What is new in this release:

• Features:
• database: "" starts without mmap of database. Less memory is used, zones are read from text zonefile.
• optimised zonefile parse code and zonefile write code.
• zonefiles-write option in nsd.conf, enabled when database is "". The server writes changed zonefiles to disk every hour.
• xfrdfile: "" disables xfrd.state. If enabled, zones that are same as before are not checked for a serial update at server start.
• include: "foo/nsd.d/*.conf" works, wildcard glob on includes.
• nsd shuts down during init process if given signal.
• log-time-ascii option, default yes, with readable timestamp in log.
• nsd-control addzone reports if zone already exists.
• Fix #564: add nsd-checkzone tool to check zonefile correctness.
• Increased default --with-max-ips from 8 to 16, this increases the number of interfaces you can specify in nsd.conf to listen to.
• Bugfixes:
• Fixed shutdown message sporadically not printed on exit (Thanks Anand Buddhdev).
• Documented zonefile %s syntax in nsd.conf man page.
• Fix manpage to put colon after zonefiles check and write.
• Change from "Zone" to "zone" with ".. serial .. is updated" log message.
• Changed maxbackoff for no-content secondary zones from 4h to 24h.
• Fix print filename of encompassing config file on read failure.
• Fix delete or rename of a lot of zones and make it take a non-enormous time.
• Speed up deletion of zone contents a lot, (56s to 1s), speeds up delete, rename and AXFR for zones.
• Fix #571: unused variable and incompatible pointer warnings when compiled on a system without INET6.
• Fix write_socket return value check in server.c (Thanks Brad Smith, Mark Kettenis).
• Fix that xfrd reaps children also if the signal is lost.
• Fix #577: makefile incorrectly installed manpages from srcdir.
• Fix #587: Default value for statistics is 0.
• Fix #553: Improve TXT parsing.
• Fix #590: rrl log does not print wildcard as a star but escaped.
• Fix #591: rrl log messages at verbosity level 1.
• fix strptime implicit declaration error on OpenBSD.
• Fix -O3 compile flag to -O2 to avoid miscompilations.
• Allow user to override the -g -O2 CFLAGS in ./configure.
• Fix endian.h include for OpenBSD.
• Remove .LP after .SH in man pages.
• Fix #600: document that provide-xfr provides AXFR and not IXFR.
• Fix rising-load-average or memory-leaks in OSes (Linux since 2.6), that keep track of all past process parents, or leak memory for them. Fix makes it so there is no very deep string of process parents.

What is new in version 4.0.0:

• documented in doc/NSD-4-features. Change configuration without restart, direct nameserver control with nsd-control, support a higher number of zones. Higher performance (compared to NSD3).
• nsdc is gone. Use kill -HUP for reload (also checks if zonefiles have changed and rereads them), and kill -TERM for quit. Or use nsd-control for detailed control.
• cron job for nsdcpatch is gone. nsd-control write creates zonefiles.
• nsd.db has a new format that compacts itself when it is changed, thus nsdc patch is no longer necessary.
• nsd.db is memory mapped, NSD needs (part of) that mmap in ram.
• tcp-count can go above 1000; epoll/kqueue support with libevent.
• nsd-control reconfig for updates with no restart (zones, keys, ..)
• nsd-control-setup to create keys for nsd-control (enable nsd-control with remote-control: yes in nsd.conf).