FreeBSD DNS

FreeBSD DNS

Introduction

This guide takes you through the setup of DNS (bind) on a FreeBSD machine. This guide assumes you know some basics about DNS. If you don't have a clue what DNS is about or how it operates please goto the library and get the book: 'Orielly: DNS/Bind' book. It is the definitive guide that most DNS admins should be familiar with.

FreeBSD DNS Concepts

It is important to understand DNS as it is core in a system like FreeBSD. In fact, FreeBSD comes with a stock with full blown DNS server and client. You don't need to install any 3rd party software to get it going. Setting up DNS on FreeBSD is trivial and shouldn't take long to get going.

Enabling DNS

First off, let's get your FreeBSD box ready for setup. This includes making sure your hostname is setup properly and running the necessary make script. First off, set your hostname:

	# hostname foo.bar.com

Now time to run the prepacked make shell script to install the proper configuration files:

	# cd /etc/namedb
	# sh make-localhost

You'll notice that I cd'd into /etc/namedb. This is where the name server config files sit on FreeBSD. The make-localhost script comes with FreeBSD and should set everything up properly. By default, it sets up a caching-only name server on your machine. The main config file is /etc/namedb/named.conf. If you need to add zones or do any slave work set it up in that file.

FreeBSD also comes with some stock reload and restart scripts:

	To reload the nameserver (without clearing cache):
	# named.reload

	To completely restart the nameserver:
	# named.restart

Verify that it's running by using 'netstat -an' and 'sockstat':

	From netstat -an: 
	.
	.
	.
	tcp4       0      0  127.0.0.1.53           *.*                    LISTEN
	tcp4       0      0  205.238.129.221.53     *.*                    LISTEN
	.
	.
	.
	udp4       0      0  127.0.0.1.53           *.*                    
	udp4       0      0  205.238.129.221.53     *.* 
	.
	.
	.

	Yep, something is listening on udp and tcp port 53.  Lets look at sockstat to see
	who it is:

	root     named    20693   20 udp4   205.238.129.221:53    *:*                  
	root     named    20693   21 tcp4   205.238.129.221:53    *:*                  
	root     named    20693   22 udp4   127.0.0.1:53          *:*                  
	root     named    20693   23 tcp4   127.0.0.1:53          *:* 

	Yep, named is running

That's all it takes to get it running!!! God bless FreeBSD! Anyhow, we need to make it start up everytime you boot up the machine. To do this, once again, edit /etc/rc.conf and add:

	named_enable="YES"

If you wish to use your nameserver for resolution on your local box. You need to edit /etc/resolv.conf and add the following lines:

	search bar.com
	nameserver 127.0.0.1

Now test it out:

	# nslookup
	Default Server:  localhost.bar.com
	Address:  127.0.0.1

	> yahoo.com.
	Server:  localhost.bar.com
	Address:  127.0.0.1

	Name:    yahoo.com
	Address:  66.218.71.198

	> exit
	#

WOW! It's actually working. How bout that! And that's all she wrote. To add zones and other DNS information consult your favorite DNS book and add your stuff to the files in /etc/namedb.