How to Create DNS Server in CentOS?

Setting up a DNS (Domain Name System) server in CentOS can be a crucial step in managing and controlling your network's domain names and IP addresses. DNS servers play a pivotal role in translating human-readable domain names into machine-readable IP addresses, facilitating seamless communication across the internet. In this guide, we will walk through the process of creating a DNS server on a CentOS system, ensuring a reliable and efficient domain resolution for your network.

Prerequisites:

Before diving into the DNS server setup, make sure you have the following:

1. A CentOS server with root or sudo access.
2. A static IP address for your CentOS server.
3. Basic knowledge of the Linux command line.

Step 1: Update System Packages

Before proceeding with the DNS server installation, ensure that your system packages are up to date by running the following commands:

sudo yum update
sudo yum upgrade

Step 2: Install BIND (Berkeley Internet Name Domain)

BIND is the most widely used DNS software on the internet. Install BIND using the following command:

sudo yum install bind bind-utils

Step 3: Configure BIND

Now, it's time to configure BIND. Open the BIND configuration file using a text editor:

sudo nano /etc/named.conf

Update the options section with your server's IP address and network information:

options {
    listen-on port 53 { 127.0.0.1; YOUR_SERVER_IP; };
    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; YOUR_NETWORK; };
    recursion yes;
};

Step 4: Create Forward and Reverse Zones

Now, define the forward and reverse zones for your domain in the configuration file. Add the following sections:

Forward Zone:

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

Reverse Zone:

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

Step 5: Create Zone Files

Create the forward and reverse zone files in the specified directory (/var/named/):

sudo nano /var/named/forward.zone

Add the following content (replace with your actual domain and IP address):

$TTL 1D
@       IN      SOA     ns1.yourdomain.com. admin.yourdomain.com. (
                        2023121601      ; Serial
                        3H              ; Refresh
                        15M             ; Retry
                        1W              ; Expire
                        1D )            ; Minimum TTL

        IN      NS      ns1.yourdomain.com.
ns1     IN      A       YOUR_SERVER_IP
www     IN      A       WWW_SERVER_IP

Step 6: Configure Reverse Zone File

Create and edit the reverse.zone file:

sudo nano /var/named/reverse.zone

Add the following content (modify with your actual information):

$TTL 1D
@       IN      SOA     ns1.yourdomain.com. admin.yourdomain.com. (
                        2023121601      ; Serial
                        3H              ; Refresh
                        15M             ; Retry
                        1W              ; Expire
                        1D )            ; Minimum TTL

        IN      NS      ns1.yourdomain.com.
1       IN      PTR     ns1.yourdomain.com.
2       IN      PTR     www.yourdomain.com.

Step 7: Set Permissions and Restart BIND

Set the correct permissions for the zone files:

sudo chown named:named /var/named/forward.zone
sudo chown named:named /var/named/reverse.zone

Restart the BIND service to apply the changes:

sudo systemctl restart named
sudo systemctl enable named

Step 8: Configure Firewall

If you have a firewall enabled, allow DNS traffic:

sudo firewall-cmd --permanent --add-service=dns
sudo firewall-cmd --reload

Step 9: Test DNS Resolution

Test your DNS server by using the nslookup command:

nslookup www.yourdomain.com

Congratulations! You have successfully set up a DNS server on CentOS, enhancing your network's domain resolution capabilities. This guide provides a foundation for managing your domain names and IP addresses efficiently. Feel free to explore advanced configurations and additional features to tailor the DNS server to your specific needs.