Configure Options

NSD can be configured using GNU autoconf’s configure script. In addition to standard configure options, one may use the following:

Environment Variables

Compiler & Linker Settings

configure

CC=compiler

Specify the C compiler. The default is gcc or cc. The compiler must support ANSI C89.

configure

CPPFLAGS=flags

Specify the C preprocessor flags. Such as -I<includedir>.

configure

CFLAGS=flags

Specify the C compiler flags. These include code generation, optimisation, warning, and debugging flags. These flags are also passed to the linker. The default for gcc is -g -O2.

configure

LD=linker

Specify the linker (defaults to the C compiler).

configure

LDFLAGS=flags

Specify linker flags.

configure

LIBS=libs

Specify additional libraries to link with.

Path Configuration Options

Directory and File Paths

`--with-configdir=dir`

NSD configuration directory, default /etc/nsd.

`--with-nsd_conf_file=path`

Pathname to the NSD configuration file, default /etc/nsd/nsd.conf.

`--with-pidfile=path`

Pathname to the NSD pidfile, default is platform specific, mostly /var/run/nsd.pid.

`--with-zonesdir=dir`

NSD default location for master zone files, default /etc/nsd/.

`--with-logfile=path`

Pathname to the default log file.

`--with-dbdir=dir`

Base directory for the xfrd zone timer state file, the zone list file and the cookie secrets file.

`--with-xfrdfile=path`

Pathname to the NSD xfrd zone timer state file.

`--with-zonelistfile=path`

Pathname to the NSD zone list file.

`--with-cookiesecretsfile=path`

Pathname to the NSD cookie secrets file.

`--with-xfrdir=path`

Pathname to where the NSD transfer dir is created.

`--with-sharedfilesdir=dir`

NSD shared files directory.

`--with-chroot=dir`

NSD default chroot directory.

User & Service Options

Process and Service Configuration

`--with-user=username`

User name or ID to answer the queries with, default is nsd.

`--with-facility=facility`

Specify the syslog facility to use. The default is LOG_DAEMON. See the syslog(3) manual page for the available facilities.

`--with-start_priority=number`

Startup priority for NSD.

`--with-kill_priority=number`

Shutdown priority for NSD.

`--with-tcp-timeout=number`

Set the default TCP timeout (in seconds). The default is 120 seconds.

Library Dependencies

External Library Configuration

`--with-ssl=path`

Specify the location of the OpenSSL libraries. OpenSSL 0.9.7 or higher is required for TSIG support.

configure

./configure --with-ssl=/usr/local/ssl

`--with-libevent=path`

Specify the location of the libevent library (or libev). Useful when the zone count is high.

configure

./configure --with-libevent=/usr/local

Use --with-libevent=no to use a builtin portable implementation (select()).

Feature Enable/Disable Options

IPv6 Support

`--disable-ipv6`

Disables IPv6 support in NSD.

configure

./configure --disable-ipv6

Statistics Options

`--disable-bind8-stats`

Disables BIND8-like statistics.

`--disable-zone-stats`

Disable per-zone statistics gathering (if enabled, it needs bind8-stats).

configure

./configure --disable-zone-stats

DNSSEC & NSEC3

`--disable-nsec3`

Disable NSEC3 support. With NSEC3 support enabled, very large zones, also non-NSEC3 zones, use about 20% more memory.

configure

./configure --disable-nsec3

Rate Limiting

`--disable-ratelimit`

Disables rate limiting, based on query name, type and source.

`--disable-ratelimit-default-is-off`

Disable this to set default of ratelimit to on (this controls the default, ratelimits can be enabled and disabled in nsd.conf).

configure

./configure --disable-ratelimit

Response Options

`--disable-minimal-responses`

Disable minimal responses. If disabled, responses are more likely to get truncated, resulting in TCP fallback. When enabled (by default) NSD will leave out RRsets to make responses fit inside one datagram, but for shorter responses the full normal response is carried.

configure

./configure --disable-minimal-responses

Development & Debugging

`--enable-checking`

Enable some internal development checks. Useful if you want to modify NSD. This option enables the standard C “assert” macro and compiler warnings.This will instruct NSD to be stricter when validating its input. This could lead to a reduced service level.

configure

./configure --enable-checking

`--enable-memclean`

Cleanup memory (at exit) for eg. valgrind, memcheck.

`--enable-log-role`

Shows the role of processes in the logfile (enable this only for debugging purposes).

Advanced Features

`--disable-dnstap`

Disable dnstap support (requires fstrm-devel, protobuf-c).

`--enable-systemd`

Compile with systemd support, and then the server notifies libsystemd when the server is up (it needs pkg-config and systemd-devel).

configure

./configure --enable-systemd

`--enable-recvmmsg`

Enable recvmmsg and sendmmsg compilation, faster but some kernel versions may have implementation problems for IPv6.

`--enable-tcp-fastopen`

Enable TCP Fast Open.

configure

./configure --enable-tcp-fastopen

`--enable-mmap`

Use mmap instead of malloc. Experimental.

`--disable-radix-tree`

You can disable the radix tree and use the red-black tree for the main lookups, the red-black tree uses less memory, but uses some more CPU.

`--enable-packed`

Enable packed structure alignment, uses less memory, but unaligned reads.

`--enable-xdp`

Enable XDP support.

configure

./configure --enable-xdp

File System Options

`--disable-largefile`

Disable large file support (64 bit file lengths). Makes off_t a 32bit length during compilation.

Root Server (Obsolete)

`--enable-root-server`

Configure NSD as a root server (obsolete).

SIMD Zone Parser Options

Parser Kernel Configuration

`--disable-westmere`

Disable Westmere (SSE4.2) parser kernel.

`--disable-haswell`

Disable Haswell (AVX2) parser kernel.

Example Configuration

configure

# Standard configuration with OpenSSL and libevent
./configure \
  --with-ssl=/usr/local/ssl \
  --with-libevent=/usr/local \
  --with-user=nsd \
  --enable-systemd

# Minimal configuration without advanced features
./configure \
  --disable-ipv6 \
  --disable-nsec3 \
  --disable-ratelimit \
  --with-libevent=no

# Development configuration
./configure \
  --enable-checking \
  --enable-memclean \
  --enable-log-role

Important Notes

If you activate --enable-checking, NSD will be stricter when validating its input. This could lead to a reduced service level and should only be used for development purposes.

The --with-libevent=no option uses a builtin portable implementation based on select(). This is useful when libevent is not available, but may have reduced performance for high zone counts.

Manual Pages

Zone Files

Technical Reference

​Environment Variables

​Path Configuration Options

​--with-configdir=dir

​--with-nsd_conf_file=path

​--with-pidfile=path

​--with-zonesdir=dir

​--with-logfile=path

​--with-dbdir=dir

​--with-xfrdfile=path

​--with-zonelistfile=path

​--with-cookiesecretsfile=path

​--with-xfrdir=path

​--with-sharedfilesdir=dir

​--with-chroot=dir

​User & Service Options

​--with-user=username

​--with-facility=facility

​--with-start_priority=number

​--with-kill_priority=number

​--with-tcp-timeout=number

​Library Dependencies

​--with-ssl=path

​--with-libevent=path

​Feature Enable/Disable Options

​--disable-ipv6

​--disable-bind8-stats

​--disable-zone-stats

​--disable-nsec3

​--disable-ratelimit

​--disable-ratelimit-default-is-off

​--disable-minimal-responses

​--enable-checking

​--enable-memclean

​--enable-log-role

​--disable-dnstap

​--enable-systemd

​--enable-recvmmsg

​--enable-tcp-fastopen

​--enable-mmap

​--disable-radix-tree

​--enable-packed

​--enable-xdp

​--disable-largefile

​--enable-root-server

​SIMD Zone Parser Options

​--disable-westmere

​--disable-haswell

​Example Configuration

​Important Notes

Build docs developers (and LLMs) love

Environment Variables

Path Configuration Options

`--with-configdir=dir`

`--with-nsd_conf_file=path`

`--with-pidfile=path`

`--with-zonesdir=dir`

`--with-logfile=path`

`--with-dbdir=dir`

`--with-xfrdfile=path`

`--with-zonelistfile=path`

`--with-cookiesecretsfile=path`

`--with-xfrdir=path`

`--with-sharedfilesdir=dir`

`--with-chroot=dir`

User & Service Options

`--with-user=username`

`--with-facility=facility`

`--with-start_priority=number`

`--with-kill_priority=number`

`--with-tcp-timeout=number`

Library Dependencies

`--with-ssl=path`

`--with-libevent=path`

Feature Enable/Disable Options

`--disable-ipv6`

`--disable-bind8-stats`

`--disable-zone-stats`

`--disable-nsec3`

`--disable-ratelimit`

`--disable-ratelimit-default-is-off`

`--disable-minimal-responses`

`--enable-checking`

`--enable-memclean`

`--enable-log-role`

`--disable-dnstap`

`--enable-systemd`

`--enable-recvmmsg`

`--enable-tcp-fastopen`

`--enable-mmap`

`--disable-radix-tree`

`--enable-packed`

`--enable-xdp`

`--disable-largefile`

`--enable-root-server`

SIMD Zone Parser Options

`--disable-westmere`

`--disable-haswell`

Example Configuration

Important Notes