Knot DNS

Knot DNS

Knot DNS is a high-performance authoritative-only DNS server which supports all key features of the domain name system including zone transfers and DNSSEC.


Knot DNS has several dependencies:
* libtool
* autoconf > 2.65
* pkg-config
* liburcu >= 0.5.4
* gnutls >= 3.0
* jansson >= 2.3
* libedit

Embedded libraries:
* lmdb               (system library is preferred)

Optional packages:
* libcap-ng >= 0.6.4 (for POSIX 1003.1e capabilities(7))
* libidn             (for IDNA2003 support in Knot utilities)
* libsystemd         (for systemd init system support)

Dependencies for building documentation:
* python-sphinx


Knot DNS may already be included in your operating system distribution and
therefore can be installed from packages (Linux), ports (BSD) or via
Homebrew (Mac). This is always preferred unless you want to test the latest
features, contribute to Knot development, or you just know what you are doing.

Following sections describe how to build Knot DNS from the source code.

1) Install prerequisites

Debian based distributions
Update the system:
$ sudo apt-get update
$ sudo apt-get upgrade

Install prerequisites:
$ sudo apt-get install \
  libtool autoconf make pkg-config liburcu-dev libgnutls28-dev libjansson-dev libedit-dev

Install optional packages to override embedded libraries:
$ sudo apt-get install liblmdb-dev

Install optional packages:
$ sudo apt-get install libcap-ng-dev libsystemd-dev libidn11-dev protobuf-c-compiler libfstrm-dev

Fedora like distributions
Update the system:
# dnf upgrade

Install basic development tools:
# dnf install @buildsys-build

Install prerequisites:
# dnf install \
  libtool autoconf pkgconfig automake userspace-rcu-devel gnutls-devel jansson-devel libedit-devel

Install optional packages to override embedded libraries:
# dnf install lmdb-devel

Install optional packages:
# dnf install libcap-ng-devel systemd-devel libidn-devel protobuf-c-devel fstrm-devel

When compiling on RHEL based system, the Fedora EPEL repository has to be
enabled. Also for RHEL 6, forward compatibility package gnutls30-devel
with newer GnuTLS is required instead of gnutls-devel.

2) Install Knot DNS

Knot DNS requires compiler to support atomic intrinsics.
GCC version at least 4.1 supports legacy atomic builtins, however 4.7
or newer is preferred. Clang supports atomics since version 2.9.

Get the source code:
$ git clone git://
Or extract source package to knot-dns directory

Compile Knot
$ cd knot-dns
$ autoreconf -if
$ ./configure
$ make

Install Knot DNS into system:
$ sudo make install
$ sudo ldconfig

NOTE: If you want to reduce zscanner compile time, use configure option --disable-fastparser.


1) Each server needs configuration file. Please see samples/knot.sample.conf,
project documentation, or man 5 knot.conf for more details.
Configuration file has to specify:
- storage for PID files, journal files etc.
- network interfaces
- served zones

E.g. use the default config file:
$ cd /etc/knot
$ mv knot.sample.conf knot.conf
Modify the config:
$ editor knot.conf

2) Prepare working directory
$ mv /var/lib/knot/

3) Start the server. This can be done by running the 'knotd' command.
Alternatively, your distribution should have an init script available, if you've
installed Knot using a binary package.

Start Knot in the foreground to see if it runs:
$ knotd -c myserver.conf

For more information, refer to the user manual or:
$ knotc -h
$ knotd -h

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