Setting up a BIND DNS Server: Difference between revisions

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= Introduction =
= Introduction =


If you are planning to set up a Samba Active Directory (AD) domain controller (DC) using the <code>BIND9_DLZ</code> back end, you have to install and configure the BIND DNS server first.
This HowTo describes how to compile and configure a basic BIND installation, that can be used as Samba DC DNS backend. Skip this guide if you already have an existing BIND installation that can be used as a Samba AD backend.


The following describes how to set up a basic BIND installation you can use as Samba AD DC back end.
If you need to setup a more complex DNS setup than what is possible with the Samba 4 internal DNS, then using BIND as the DNS backend is recommended.




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= Installing BIND =
= Installing BIND =


For a list of supported BIND versions, see [[BIND9_DLZ_DNS_Back_End#Configuring_the_BIND9_DLZ_Module|Configuring the BIND9_DLZ module]].
The use of BIND as a backend for your Samba Active Directory Domain Controller is currently only supported in versions 9.8 and 9.9. Users of bind 9.7 are strongly encouraged to upgrade! If this is not possible, refer to the section [[Configure_BIND_as_backend_for_Samba_AD#BIND_9.7_2|DNS dynamic updates via Kerberos for BIND 9.7]] for instructions on configuring BIND 9.7.


{{Imbox
If you install BIND from the repositories of your distribution, you can skip the following two steps, but make sure that it was compiled with the '--with-gssapi' and '--with-dlopen' options (see below) before using it as the Samba AD DNS backend.
| type = note
| text = You can not run BIND in a changed root environment, because the <code>BIND9_DLZ</code> must be able to access the Samba Active Directory (AD) database files directly.
}}






== Downloading ==
== Package Installation ==


Installing BIND using packages provided with your distribution is the recommended way. Select this installation mode for an easy installation and to automatically receive updates when available. For details how to install packages, see the distribution's package manager documentation.
Download your desired and Samba 4 supported version from [https://www.isc.org/software/bind https://www.isc.org/software/bind].


Make sure that your package provider compiled BIND using the following options:
* <code>--with-gssapi=yes</code> or <code>--with-gssapi=/usr</code> (or similar) for secure dynamic DNS updates using Kerberos
* <code>--with-dlopen</code> dynamically loadable zones (DLZ)


{{Imbox
| type = note
| text = Later versions of Bind9.9.x have the <code>--with-dlopen</code> option builtin and is not shown by the following command. This happened around Bind 9.9.4
}}


To list the build options:
== Compiling BIND ==
# named -V
BIND 9.x.y built with ... '--with-dlopen=yes' '--with-gssapi=yes' ...



To use BIND 9.8.1 or later as Samba AD backend, at least the following two configure options are required:


== Compiling and Installing BIND ==

Use this installation mode if you are an advanced user and know how to compile software.


=== Downloading the Sources ===

Download a supported BIND version from https://www.isc.org/software/bind.



=== Compiling BIND ===

* Pass at least the following parameters to the <code>configure</code> command:


# ./configure --with-gssapi=/usr/include/gssapi --with-dlopen=yes
# ./configure --with-gssapi=/usr/include/gssapi --with-dlopen=yes


: Add further parameters, if required.
Please check if there are other options you require for your environment. If you are building BIND 9.8.0, you must use '--with-dlz-dlopen=yes' instead of '--with-dlopen=yes'.


To build and install:
* To build and install, run:


# make
# make
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=== Adding a User and Group for BIND ===
= Configuration =


For security reasons, do not run BIND as <code>root</code> user.
== Setting up a basic named.conf ==


To create a <code>named</code> group using GID <code>25</code>:
The following example is a basic 'named.conf' for a pure minimal BIND installation without any Samba AD parts. We will add the Samba required parameters later.


# /etc/named.conf
# groupadd -g 25 named

# Global BIND configuration options
To create a <code>named</code> account with UID <code>25</code>, primary group <code>named</code>, home directory <code>/var/named/</code>, and without a valid shell:

# useradd -u 25 -g named -d /var/named -M -s /sbin/nologin named

For details, see the <code>useradd (8)</code> and <code>groupadd (8)</code> man page.





= Configuring BIND =

== Setting up a named.conf file ==

To locate the directory, BIND uses to read the <code>named.conf</code> file:

# named -V
BIND 9.x.y built with ... '--sysconfdir=/etc' ...

In the previous example, BIND reads the configuration from the <code>/etc/named.conf</code> file.

The following is a basic configuration file:

# Global Configuration Options
options {
options {
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empty-zones-enable no;
empty-zones-enable no;
# IP addresses and network ranges allowed to query the DNS server:
allow-query {
allow-query {
127.0.0.1;
127.0.0.1;
10.1.1.0/24;
10.99.1.0/24;
# add other networks you want to allow to query your DNS
};
};
# IP addresses and network ranges allowed to run recursive queries:
# (Zones not served by this DNS server)
allow-recursion {
allow-recursion {
127.0.0.1;
10.1.1.0/24;
10.1.1.0/24;
# add other networks you want to allow to do recursive queries
};
};
# Forward queries that can not be answered from own zones
# to these DNS servers:
forwarders {
forwarders {
# Google public DNS server here - replace with your own if necessary
8.8.8.8;
8.8.8.8;
8.8.4.4;
8.8.4.4;
};
};
# Disable zone transfers
allow-transfer {
allow-transfer {
# this config is for a single master DNS server
none;
none;
};
};
};
# Root Servers
};
# (Required for recursive DNS queries)
# Root servers (required zone for recursive queries)
zone "." {
zone "." {
type hint;
type hint;
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};
};
# Required localhost forward-/reverse zones
# localhost zone
zone "localhost" {
zone "localhost" {
type master;
type master;
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};
};
# 127.0.0. zone.
zone "0.0.127.in-addr.arpa" {
zone "0.0.127.in-addr.arpa" {
type master;
type master;
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};
};


For details about the used parameters and options, see the <code>named.conf (5)</code> man page.
We chose '/var/named' as directory in 'named.conf' to be the place where our zonefiles, etc. reside. If you want to place them on a different location, please regard this in all further instructions.


The previous example does not contain the <code>BIND9_DLZ</code> configuration required for setting up a Samba AD DNS server. For details how to set up the module, see [[BIND9_DLZ_DNS_Back_End|BIND9_DLZ DNS Back End]].
For more details on the parameters used in the sample 'named.conf', see 'man 5 named.conf'.


{{Imbox
| type = important
| text = You must not add the AD domain forward or reverse zone records to the named.conf files, these zones are stored dynamically in AD.
}}




== Adding a user and group for BIND ==


== Downloading the DNS Root Servers List ==
If you don't want to run bind as root (and I'm sure you don't want that!), we add an account and group.


* Download the latest list of the DNS root servers to the <code>/var/named/named.root</code> file:
First check if we have an existing `named` group:


# wget -q -O /var/named/named.root http://www.internic.net/zones/named.root
# getent group|grep named


Add the user and group if none exists (adapt the UID/GID if required) :
* Enable the BIND user to read the root servers list:


# groupadd -g 25 named
# chown root:named /var/named/named.root
# useradd -g named -u 25 -d /var/named -M -s /sbin/nologin named
# chmod 640 /var/named/named.root


{{Imbox
| type = note
| text = Optionally, set up a Cron job to automatically update the file.
}}




== Getting the root name server list ==


== Creating the localhost Zone File ==
Download the root name server list from InterNIC:


* Create the <code>localhost</code> forward zone in the <code>/var/named/master/localhost.zone</code> file:
# wget -q -O /var/named/named.root http://www.internic.net/zones/named.root
# chown named:named /var/named/named.root

To have always the current file, you can add a cronjob to automatically download.



== Creating the localhost zone file ==

Create a forward zone file ('/var/named/master/localhost.zone') for your 'localhost' zone:


$TTL 3D
$TTL 3D
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IN A 127.0.0.1
IN A 127.0.0.1


* Enable the BIND user to read the zone file:
# chown named:named /var/named/master/localhost.zone
# chmod 640 /var/named/master/localhost.zone




== Creating the 0.0.127.in-addr.arpa zone file ==


Create a reverse zone file ('/var/named/master/0.0.127.zone') for your '0.0.127.in-addr.arpa' zone:
== Creating the 0.0.127.in-addr.arpa Zone File ==

* Create the <code>0.0.127.in-addr.arpa</code> reverse zone in the <code>/var/named/master/0.0.127.zone</code> file:


$TTL 3D
$TTL 3D
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* Enable the BIND user to read the zone file:


# chown named:named /var/named/master/0.0.127.zone
== Set permissions on the zone files ==
# chmod 640 /var/named/master/0.0.127.zone


# chown named:named /var/named/master/*.zone
# chmod 640 /var/named/master/*.zone








= Starting the Daemon =


To start the BIND daemon as the <code>named</code> user, run
= Starting BIND =


# named -u named
# named -u named


Alternatively, use your operating system tools, such as <code>systemctl</code> or <code>service</code>, to start the daemon. See you distribution's documentation for details.
If the configuration is valid, you should see no errors on the console and in the system logfile.


{{Imbox
To have BIND automatically started at boot time, it's recommended to create a init.d script or start it by systemd.
| type = note
| text = Enable the daemon to start automatically when the system boots. For details, see your distribution's documentation.
}}








= Testing Your Zones =


The following examples query the DNS service on the local machine (<code>127.0.0.1</code>):
= Testing your zone =


To test the <code>localhost</code> forward zone:
Now we will try to lookup our zone entries. We tell the 'host' command to use the resolver on 127.0.0.1, so that we don't query a foreign DNS server that is also configured in '/etc/resolv.conf'.


# host -t A localhost 127.0.0.1
First check the forward lookup for 'localhost':
# host localhost. 127.0.0.1
Using domain server:
Using domain server:
Name: 127.0.0.1
Name: 127.0.0.1
Address: 127.0.0.1#53
Address: 127.0.0.1#53
Aliases:
Aliases:
localhost has address 127.0.0.1
localhost has address 127.0.0.1


To test the <code>0.0.127.in-addr.arpa</code> reverse zone:
And then the reverse lookup for '127.0.0.1':

# host 127.0.0.1 127.0.0.1
# host -t PTR 127.0.0.1 127.0.0.1
Using domain server:
Using domain server:
Name: 127.0.0.1
Name: 127.0.0.1
Address: 127.0.0.1#53
Address: 127.0.0.1#53
Aliases:
Aliases:
1.0.0.127.in-addr.arpa domain name pointer localhost.
1.0.0.127.in-addr.arpa domain name pointer localhost.


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= Configuring BIND as Samba Active Directory backend =


= Configuring the BIND9_DLZ module =
See [[Configure_BIND_as_backend_for_Samba_AD|Configure BIND as backend for Samba AD]].

For details, see See [[BIND9_DLZ_DNS_Back_End|BIND9_DLZ DNS Back End]].





----
[[Category:Active Directory]]
[[Category:DNS]]

Revision as of 18:26, 2 January 2018

Introduction

If you are planning to set up a Samba Active Directory (AD) domain controller (DC) using the BIND9_DLZ back end, you have to install and configure the BIND DNS server first.

The following describes how to set up a basic BIND installation you can use as Samba AD DC back end.



Installing BIND

For a list of supported BIND versions, see Configuring the BIND9_DLZ module.


Package Installation

Installing BIND using packages provided with your distribution is the recommended way. Select this installation mode for an easy installation and to automatically receive updates when available. For details how to install packages, see the distribution's package manager documentation.

Make sure that your package provider compiled BIND using the following options:

  • --with-gssapi=yes or --with-gssapi=/usr (or similar) for secure dynamic DNS updates using Kerberos
  • --with-dlopen dynamically loadable zones (DLZ)

To list the build options:

# named -V
BIND 9.x.y built with ... '--with-dlopen=yes' '--with-gssapi=yes' ...



Compiling and Installing BIND

Use this installation mode if you are an advanced user and know how to compile software.


Downloading the Sources

Download a supported BIND version from https://www.isc.org/software/bind.


Compiling BIND

  • Pass at least the following parameters to the configure command:
# ./configure --with-gssapi=/usr/include/gssapi --with-dlopen=yes
Add further parameters, if required.
  • To build and install, run:
# make
# make install


Adding a User and Group for BIND

For security reasons, do not run BIND as root user.

To create a named group using GID 25:

# groupadd -g 25 named

To create a named account with UID 25, primary group named, home directory /var/named/, and without a valid shell:

# useradd -u 25 -g named -d /var/named -M -s /sbin/nologin named

For details, see the useradd (8) and groupadd (8) man page.



Configuring BIND

Setting up a named.conf file

To locate the directory, BIND uses to read the named.conf file:

# named -V
BIND 9.x.y built with ... '--sysconfdir=/etc' ...

In the previous example, BIND reads the configuration from the /etc/named.conf file.

The following is a basic configuration file:

# Global Configuration Options
options {

    auth-nxdomain yes;
    directory "/var/named";
    notify no;
    empty-zones-enable no;

    # IP addresses and network ranges allowed to query the DNS server:
    allow-query {
        127.0.0.1;
        10.99.1.0/24;
    };

    # IP addresses and network ranges allowed to run recursive queries:
    # (Zones not served by this DNS server)
    allow-recursion {
        127.0.0.1;
        10.1.1.0/24;
    };

    # Forward queries that can not be answered from own zones
    # to these DNS servers:
    forwarders {
        8.8.8.8;
        8.8.4.4;
    };

    # Disable zone transfers 
    allow-transfer {
        none;
    };
 };

# Root Servers
# (Required for recursive DNS queries)
zone "." {
   type hint;
   file "named.root";
};

# localhost zone
zone "localhost" {
    type master;
    file "master/localhost.zone";
};

# 127.0.0. zone.
zone "0.0.127.in-addr.arpa" {
    type master;
    file "master/0.0.127.zone";
};

For details about the used parameters and options, see the named.conf (5) man page.

The previous example does not contain the BIND9_DLZ configuration required for setting up a Samba AD DNS server. For details how to set up the module, see BIND9_DLZ DNS Back End.


Downloading the DNS Root Servers List

  • Download the latest list of the DNS root servers to the /var/named/named.root file:
# wget -q -O /var/named/named.root http://www.internic.net/zones/named.root
  • Enable the BIND user to read the root servers list:
# chown root:named /var/named/named.root
# chmod 640 /var/named/named.root


Creating the localhost Zone File

  • Create the localhost forward zone in the /var/named/master/localhost.zone file:
$TTL 3D

$ORIGIN localhost.

@       1D      IN     SOA     @       root (
                       2013050101      ; serial
                       8H              ; refresh
                       2H              ; retry
                       4W              ; expiry
                       1D              ; minimum
                       )

@       IN      NS      @
        IN      A       127.0.0.1
  • Enable the BIND user to read the zone file:
# chown named:named /var/named/master/localhost.zone
# chmod 640 /var/named/master/localhost.zone


Creating the 0.0.127.in-addr.arpa Zone File

  • Create the 0.0.127.in-addr.arpa reverse zone in the /var/named/master/0.0.127.zone file:
$TTL 3D

@       IN      SOA     localhost. root.localhost. (
                        2013050101      ; Serial
                        8H              ; Refresh
                        2H              ; Retry
                        4W              ; Expire
                        1D              ; Minimum TTL
                        )

       IN      NS      localhost.

1      IN      PTR     localhost.


  • Enable the BIND user to read the zone file:
# chown named:named /var/named/master/0.0.127.zone
# chmod 640 /var/named/master/0.0.127.zone



Starting the Daemon

To start the BIND daemon as the named user, run

# named -u named

Alternatively, use your operating system tools, such as systemctl or service, to start the daemon. See you distribution's documentation for details.



Testing Your Zones

The following examples query the DNS service on the local machine (127.0.0.1):

To test the localhost forward zone:

# host -t A localhost 127.0.0.1
Using domain server:
Name: 127.0.0.1
Address: 127.0.0.1#53
Aliases: 
localhost has address 127.0.0.1

To test the 0.0.127.in-addr.arpa reverse zone:

# host -t PTR 127.0.0.1 127.0.0.1
Using domain server:
Name: 127.0.0.1
Address: 127.0.0.1#53
Aliases: 
1.0.0.127.in-addr.arpa domain name pointer localhost.



Configuring the BIND9_DLZ module

For details, see See BIND9_DLZ DNS Back End.