Master DNS Basics and BIND Server Setup on Linux: A Step-by-Step Guide

DNS Overview

DNS (Domain Name System) is a client/server mechanism that translates computer names to IP addresses, serving as a fundamental Internet service and widely used in enterprise networks.

Functions of DNS Servers

Forward resolution: find IP address from host name. Reverse resolution: find host name from IP address.

Distributed Data Structure of DNS

DNS Query Types

Recursive query: most clients use this method to resolve domain names via a DNS server.
Iterative query: most DNS servers use this method to resolve domain names via other DNS servers.

Types of DNS Servers

Cache DNS Server

Cache DNS server (also called caching server) obtains domain‑>IP records from other DNS servers and caches the results locally to speed up repeated queries.

Primary DNS Server

Primary DNS server: the authoritative server for a DNS zone, uniquely responsible for maintaining all domain‑>IP mappings in that zone.

Secondary DNS Server

Secondary DNS server (also called slave): its domain‑>IP records are sourced from the primary server.

BIND DNS Service Basics

BIND (Berkeley Internet Name Daemon) is the standard DNS server.
Official site: https://www.isc.org/
Server program: /usr/sbin/named
Service script: /etc/init.d/named
Default listening port: 53
Main configuration file: /etc/named.conf
Data files stored in: /var/named/chroot/var/named/

Configuration File Overview

/etc/named.conf

options {
    listen-on port 53 { 127.0.0.1; };
    listen-on-v6 port 53 { ::1; };
    directory "/var/named";
    dump-file "/var/named/data/cache_dump.db";
    statistics-file "/var/named/data/named_stats.txt";
    memstatistics-file "/var/named/data/named_mem_stats.txt";
    allow-query { localhost; };
    recursion yes;
    dnssec-enable yes;
    dnssec-validation yes;
    dnssec-lookaside auto;
    bindkeys-file "/etc/named.iscdlv.key";
};
logging {
    channel default_debug {
        file "data/named.run";
        severity dynamic;
    };
};
zone "." IN {
    type hint;
    file "named.ca";
};
include "/etc/named.rfc1912.zones";

/etc/named.rfc1912.zones

zone "localhost.localdomain" IN {
    type master;
    file "named.localhost";
    allow-update { none; };
};
zone "localhost" IN {
    type master;
    file "named.localhost";
    allow-update { none; };
};
zone ".0.ip4.arpa" IN {
    type master;
    file "named.loopback";
    allow-update { none; };
};
zone "1.0.0.127.in-addr.arpa" IN {
    type master;
    file "named.loopback";
    allow-update { none; };
};
zone "0.in-addr.arpa" IN {
    type master;
    file "named.empty";
    allow-update { none; };
};

/var/named/named.localhost

$TTL 1D
@ IN SOA lzy.com. root.invalid. (
    0 ; serial
    1D ; refresh
    1H ; retry
    1W ; expire
    3H ) ; minimum
    NS dns.lzy.com.
    A 127.0.0.1
    AAAA ::1

Setting Up a DNS Server

Install BIND

yum install bind

Start and Enable Service

systemctl start named.service
systemctl enable named.service

Configure Main File

vim /etc/named.conf
# change to
listen-on-v6 port 53 { any; };
allow-query { any; };

Configure Zones

Forward zone example:

zone "lzy.com." IN {
    type master;
    file "lzy.com.zone";
    allow-update { none; };
};

Reverse zone example:

zone "134.168.192.in-addr.arpa" IN {
    type master;
    file "134.168.192.zone";
    allow-update { none; };
};

Create Zone Files

cp /var/named/named.empty /var/named/lzy.com.zone
cp /var/named/named.empty /var/named/134.192.168.zone
chown :named lzy.com.zone

Forward Zone Content Example

$TTL 3H
@ IN SOA lzy.com. root.lzy.com. (
    0 ; serial
    1D ; refresh
    1H ; retry
    1W ; expire
    3H ) ; minimum
    NS dns.lzy.com.
    dns A 192.168.134.139
    www A 192.168.134.139

Reverse Zone Content

# similar steps for reverse zone file

Network Interface Configuration

vim /etc/sysconfig/network-scripts/ifcfg-ens33
BOOTPROTO=static
IPADDR1=192.168.134.139
NETMASK=255.255.255.0
GATEWAY=192.168.134.2
DNS1=192.168.134.139

Start DNS Service and Verify

systemctl start named.service
named-checkconf
nslookup example.com

Client Configuration

vim /etc/resolv.conf
nameserver 192.168.137.22