Bind

Berkeley Internet Name Domain (BIND) is an authoritative, recursive DNS nameserver. It was developed as the reference implementation of the modern DNS system.

Sometimes referred to as BIND9, the binary is named(8).

Contents

Bind

Installation

Most Linux and BSD distributions offer a bind package. Supporting programs like dig(1) are sometimes split into a separate package named like dnsutils.

For systemd-capable systems, start and enable named.service.

For BSD distributions, try:

/etc/rc.d/named start

To launch the server on startup, update /etc/rc.conf:

named_enable="YES"

Containers

A Docker container image is available for the current and stable releases. These are available from DockerHub as docker.io/internetsystemsconsortium/bind9 (or simply internetsystemsconsortium/bind9 when using docker(1) specifically).

Note that this image works automatically as a recursive resolver. To use as an authoritative resolver, additional configuration and bind mounts are necessary. Compare the below:

docker run \
  --name=bind-recursive \
  --restart=always \
  --publish 53:53/udp \
  --publish 53:53/tcp \
  --publish 127.0.0.1:953:953/tcp \
  internetsystemsconsortium/bind9:9.18

docker run \
  --name=bind-authoritative \
  --restart=always \
  --publish 53:53/udp \
  --publish 53:53/tcp \
  --publish 127.0.0.1:953:953/tcp \
  --volume /etc/bind \
  --volume /var/cache/bind \
  --volume /var/lib/bind \
  --volume /var/log \
  internetsystemsconsortium/bind9:9.18

Configuration

named(8) is configured in /etc/named.conf. A basic configuration file is:

options {
    directory "/var/named";
    dump-file "/var/named/data/cache_dump.db";
    statistics-file "/var/named/data/named_stats.txt";

    dnssec-validation auto;

    listen-on { 127.0.0.1; 192.168.1.1; };
    listen-on-v6 { ::1; };
    allow-query { 127.0.0.1; 192.168.1.0/24; };
    recursion yes;
    allow-recursion { 127.0.0.1; 192.168.1.0/24; };
};

To check the configuration of named(8), run...

named-checkconf /etc/named.conf

Resursive DNS

To enable recursive DNS, simply include recursion yes;.

If allow-recursion is not set (see above), then named(8) falls back on allow-query-cache, then on allow-query, and finally a default of localnets and localhost.

Local Domains

For local domains, named(8) takes both a forward and reverse zone file.

zone "example.com" IN {
    type primary;
    file "/var/named/primary/example.com";
    allow-update { none; };
};

zone "1.168.192.in-addr.arpa" IN {
    type primary;
    file "/var/named/reverse/192.168.1";
    allow-update { none; };
};

Note that primary zones have historically been called master zones. This terminology will still be found in many documents, and the two are equivalent in practice, but upstream prefers the former.

For details on zone files, see here.

DNSSEC

named(8) can be configured to sign DNS. The keys should be saved in /var/named/primary.

First, update the FORWARD zone configuration, in /etc/named.conf.

zone "example.com" IN {
    type primary;
    file "/var/named/primary/example.com";
    allow-update { none; };

    auto-dnssec maintain;
    inline-signing yes;
    key-directory "primary/";
};

Then generate the DNSSEC keys themselves. Run...

dnssec-keygen -a NSEC3RSASHA1 -b 2048 -n ZONE example.com
dnssec-keygen -f KSK -a NSEC3RSASHA1 -b 4096 -n ZONE example.com