Page 112 - DCAP602_NETWORK_OPERATING_SYSTEMS_I

Network Operating Systems-I

notes Some versions of BIND will come with a /etc/amed.conf file configured to work as a caching
nameserver which can be transformed to an authoritative nameserver by adding the correct
references to your zone files. Please proceed to the next section if this is the case with your version
of BIND.
In additional cases the named.conf configuration file may be hard to find. Some versions of
Linux install BIND as a default caching nameserver using a file names /etc/named.caching-
nameserver.conf for its configuration. In such cases BIND becomes an authoritative nameserver
when a correctly configured /etc/named.conf file is created.

Note BIND comes with samples of all the primary files you need. Below Table
explains their names and purpose in more detail.

The Primary BIND Configuration Files
file Description
/etc/named.conf The main configuration file that lists the location
of all your domain’s zone files
/etc/named.rfc1912.zones Base configuration file for a caching name
server.
/var/named/named.ca A list of the 13 root authoritative DNS servers.

The first task is to make sure your DNS server will listening of requests on all the required
network interfaces. The options section of named.conf may be configured to listen completely on
its internal hidden localhost interface with an IP address of 127.0.0.1 as we see in this example.

# File: /etc/named.conf
Options {
Listen-on port 53 {127.0.0.1; };
};
If other devices are going to rely on your server for queries, then you’ll need to either modify
this or add a selected number of IP addresses on your server. In this example, we allow queries
on any interface.

Listen-on port 53 {any ;};
In this example, we allow queries on localhost and address 192.168.1.100.
listen-on port 53 { 127.0.0.1; 192.168.1.100; };
Always make sure localhost, 127.0.0.1 is included.
While it is not required, it is a good practice to configure your DNS server’s named.conf file to
support BIND views. This will be discussed next.

Configuring BIND Views in named.conf

Our sample scenario believes that DNS queries will be coming from the Internet and that the
zone files will return information related to the external 97.158.253.26 address of the Web server.
What do the PCs on your home network need to see? They need to see DNS references to the
real IP address of the Web server, 192.168.1.100, because NAT won’t work properly if a PC on
your home network attempts to connect to the external 97.158.253.26 NAT IP address of your

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