How to Setup Your Own DNS Server on Ubuntu & Debian

Domain Name System (DNS) is a hierarchical distributed naming system for computers connected over a network. It resolves IP address correspondence to a domain name. There are four types of DNS servers. Many of the popular web (cloud) hosting providers already provide DNS servers for their clients but if you want to set up your own DNS server, go through this article.

This article will help you to configure DNS server using bind9 packages on a Ubuntu, Debian, and LinuxMint systems. Bind is also known as named service.

The CentOS or Redhat users can follow this article to set up DNS server.

Step 1 – Install DNS (bind9) Packages

Bind9 is the most popular DNS server used worldwide. It is available under default package repositories. So just open a terminal and execute the following commands to install the bind9 packages.

sudo apt update 
sudo apt install bind9 -y 

Step 2 – Create Forward Zone File

As we are using a temporary domain named example.net. Create a forward DNS zone file under /etc/bind directory.

sudo vi /etc/bind/example.net.zone 

Add the following content

; Forward Zone file for example.net
$TTL 14400
@      86400    IN      SOA     ns1.example.net. webmaster.example.net. (
                3013040200      ; serial, todays date+todays
                86400           ; refresh, seconds
                7200            ; retry, seconds
                3600000         ; expire, seconds
                86400          ; minimum, seconds
      )
ns1             IN A 192.168.1.212
ns2             IN A 192.168.1.212
example.net.   86400  IN        NS      ns1.example.net.
example.net.   86400  IN        NS      ns2.example.net.
example.net.          IN        A       192.168.1.100
www                   IN        CNAME   example.net.

Save the file and verify the file syntax:

named-checkzone example.net /etc/bind/example.net.zone 

On successful, an OK message will appear on the output screen.

Step 3 – Create Reverse Zone File

Generally, reverse DNS configuration is not required, but in some cases, you may need to configure it. This is used to resolve the domain name corresponding to an IP address. For example, we are using the 192.168.1.0/32 IP range in our intranet. Create reverse DNS file named /etc/bind/db.1.168.192 with following content.

sudo vi /etc/bind/db.1.168.192 

and add following content

; BIND reverse data file for local loopback interface
;
$TTL    604800
@ IN SOA ns1.example.net. root.ns1.example.net. (
                     3013040200         ; Serial
                         604800         ; Refresh
                          86400         ; Retry
                        2419200         ; Expire
                         604800 )       ; Negative Cache TTL
;
@       IN      NS      ns1.example.net.
100     IN      PTR     example.net.
101     IN      PTR     otherdomain.com.

Save the file and verify the file syntax:

named-checkzone 192.168.01.0/32 /etc/bind/db.1.168.192 

On successful, an OK message will appear on the output screen.

Step 4 – Update Bind9 Main Configuration

You have created one forward zone and reverse zone configuration file. Next, edit the bind configuration file /etc/bind/named.conf.local and add the forward and reverse zone entries like below.

sudo vi /etc/bind/named.conf.local 

Append following content

zone "example.net" IN {
        type master;
        file "/etc/bind/example.net.zone";
};

zone "1.168.192.in-addr.arpa" {
        type master;
        file "/etc/bind/db.1.168.192";
};

Save the file and check the configuration files:

named-checkconf  /etc/bind/named.conf.local 
named-checkconf  /etc/bind/named.conf 

On successful, nothing will appear on the output screen.

Step 5 – Restart bind9 Service

Once all the configuration files are verified, You can restart the bind9 service o apply changes.

sudo systemctl restart bind9 

sudo systemctl status bind9 

Output 
● named.service - BIND Domain Name Server
     Loaded: loaded (/lib/systemd/system/named.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2022-04-25 12:17:31 IST; 2h 16min ago
       Docs: man:named(8)
    Process: 10725 ExecStart=/usr/sbin/named $OPTIONS (code=exited, status=0/SUCCESS)
   Main PID: 10726 (named)
      Tasks: 4 (limit: 2271)
     Memory: 5.6M
        CPU: 146ms
     CGroup: /system.slice/named.service
             └─10726 /usr/sbin/named -u bind

The bind9 service should be active and running.

Step 6 – Verify the Setup

Finally, the DNS server is successfully configured and ready to use. Make sure your client system is using your DNS server as the default DNS server. Let’s verify that DNS is properly responding to queries. Below is example commands to test it.

Verify Forward Zone:

dig example.net 

Output 
; <<>> DiG 9.16.1-Ubuntu <<>> example.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42007
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: b8e8bae7636ea5990100000062665dfb3fce096db82322ba (good)
;; QUESTION SECTION:
;example.net.                   IN      A

;; ANSWER SECTION:
example.net.            14400   IN      A       192.168.1.100

;; Query time: 4 msec
;; SERVER: 192.168.1.212#53(192.168.1.212)
;; WHEN: Mon Apr 25 14:04:08 IST 2022
;; MSG SIZE  rcvd: 84

Verify Reverse Zone:

dig -x 192.168.1.100 

Output 
; <<>> DiG 9.16.1-Ubuntu <<>> -x 192.168.1.100
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26175
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: df64db0c13af750e0100000062665e1e52dc99d0a2d5dd41 (good)
;; QUESTION SECTION:
;100.1.168.192.in-addr.arpa.    IN      PTR

;; ANSWER SECTION:
100.1.168.192.in-addr.arpa. 604800 IN   PTR     example.net.

;; Query time: 0 msec
;; SERVER: 192.168.1.212#53(192.168.1.212)
;; WHEN: Mon Apr 25 14:04:43 IST 2022
;; MSG SIZE  rcvd: 108

Conclusion

This tutorial describes you set up a DNS server on Ubuntu, Debian, and Linux Mint systems.