In Internet computing, NSD (for "name server daemon") is an
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
Domain Name System (DNS)
server
Server may refer to:
Computing
*Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients
Role
* Waiting staff, those who work at a restaurant or a bar attending customers and su ...
. It was developed by
NLnet Labs of
Amsterdam in cooperation with the
RIPE NCC, from scratch as an authoritative name server (i.e., not implementing the recursive caching function by design). The intention of this development is to add variance to the "gene pool" of DNS implementations
used by higher level name servers and thus increase the resilience of DNS against software flaws or exploits.
NSD uses
BIND-style zone-files (zone-files used under BIND can usually be used unmodified in NSD, once entered into the NSD configuration).
NSD uses zone information compiled via
zonec into a binary database file (
nsd.db) which allows fast startup of the NSD name-service daemon, and allows syntax-structural errors in Zone-Files to be flagged at compile-time (before being made available to NSD service itself).
The collection of programs/processes that make-up NSD are designed so that the NSD daemon itself runs as a non-privileged user and can be easily configured to run in a
Chroot jail
A chroot on Unix and Unix-like operating systems is an operation that changes the apparent root directory for the current running process and its children. A program that is run in such a modified environment cannot name (and therefore normally ...
, such that security flaws in the NSD daemon are not so likely to result in system-wide compromise as without such measures.
As of May, 2018, four of the
Internet root nameservers are using NSD:
* k.root-servers.net was switched to NSD on February 19, 2003.
* One of the 2 load-balanced servers for h.root-servers.net (called "H1", "H2") was switched to NSD, and now there are 3 servers all running NSD (called "H1", "H2", "H3").
* l.root-servers.net switched to NSD on February 6, 2007.
* d.root-servers.net was switched to NSD in May 2018.
Several other TLDs use NSD for part of their servers.
See also
*
Unbound
Unbound may refer to:
Arts, entertainment, and media Music
*Unbound, formerly the name of Deathbound, a four-piece death metal band from Vaasa, Finland
*''Unbound'', an album by Merciless, 1994
*"Unbound", a song by Ásgeir Trausti, 2017
*"Unboun ...
, a recursive
DNS server
A name server refers to the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet. The most important function of DNS servers is the translation (resolution) of human-memorable domain names (example. ...
, also developed by NLnet Labs
*
Comparison of DNS server software
References
External links
* {{official website
NSD License
DNS software
Free network-related software
DNS server software for Linux
Software using the BSD license