Domain Name System (in short, DNS) is an internet service that is used to resolve Domain Name to IP Address and vice versa.
BIND (Berkeley Internet Name Domain) provides the functionality of the name to ip conversion.
This post will help you configure DNS server on Debian 10 / Debian 9.
Environment
| Domain Name: itzgeek.local | ||
|---|---|---|
| ns1.itzgeek.local | 192.168.0.10 | Master DNS Server |
Prerequisites
Update the repository index.
sudo apt-get update
Make sure the DNS server has a static IP address.
READ: How to configure static ip address in Debian
Install DNS Server
The package name of the DNS server in Debian is bind9 and is available in the base repository. You can use apt command to install bind9 package.
sudo apt-get install -y bind9 bind9utils bind9-doc dnsutils
Configure DNS Server
The /etc/bind/ is the configuration directory of bind9, holds configuration files and zone lookup files. The global configuration file is /etc/bind/named.conf.
Create Zones
Let us begin by creating a forward zone for your domain.
You should not use the global configuration file for the local DNS zone rather you can use /etc/bind/named.conf.local file.
sudo nano /etc/bind/named.conf.local
Forward Zone
The following is the forward zone entry for the itzgeek.local domain in the named.conf.local file.
zone "itzgeek.local" IN { //Domain name
type master; //Primary DNS
file "/etc/bind/forward.itzgeek.local.db"; //Forward lookup file
allow-update { none; }; // Since this is the primary DNS, it should be none.
};
Reverse Zone
The following is for the reverse zone in the named.conf.local file.
zone "0.168.192.in-addr.arpa" IN { //Reverse lookup name, should match your network in reverse order
type master; // Primary DNS
file "/etc/bind/reverse.itzgeek.local.db"; //Reverse lookup file
allow-update { none; }; //Since this is the primary DNS, it should be none.
};
Create Zone lookup file
Once zones are created, you can go ahead and create zone data files for the forward zone and reverse zone.
Forward Zone
Copy the sample entries to zone file called forward.itzgeek.local.db for the forward zone under /etc/bind directory.
Record types in the zone file,
SOA – Start of Authority
NS – Name Server
A – A record
MX – Mail for Exchange
CN – Canonical Name
Domain names should end with a dot (.).
sudo cp /etc/bind/db.local /etc/bind/forward.itzgeek.local.db
Edit the zone.
sudo nano /etc/bind/forward.itzgeek.local.db
Update the content as shown below.
;
; BIND data file for local loopback interface
;
$TTL 604800
@ IN SOA ns1.itzgeek.local. root.itzgeek.local. (
2 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
; Commentout below three lines
;@ IN NS localhost.
;@ IN A 127.0.0.1
;@ IN AAAA ::1
;Name Server Information
@ IN NS ns1.itzgeek.local.
;IP address of Name Server
ns1 IN A 192.168.0.10
;Mail Exchanger
itzgeek.local. IN MX 10 mail.itzgeek.local.
;A – Record HostName To Ip Address
www IN A 192.168.0.100
mail IN A 192.168.0.150
;CNAME record
ftp IN CNAME www.itgeek.local.
Reverse Zone
Copy the sample entries to zone file called reverse.itzgeek.local.db for the reverse zone under /etc/bind directory and create reverse pointers for the above forward zone records.
PTR – Pointer
SOA – Start of Authority
sudo cp /etc/bind/db.127 /etc/bind/reverse.itzgeek.local.db
Edit the reverse zone file.
sudo nano /etc/bind/reverse.itzgeek.local.db
Update the content as shown below.
;
; BIND reverse data file for local loopback interface
;
$TTL 604800
@ IN SOA itzgeek.local. root.itzgeek.local. (
2 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
; Commentout below two lines
;@ IN NS localhost.
;1.0.0 IN PTR localhost.
;Name Server Information
@ IN NS ns1.itzgeek.local.
;Reverse lookup for Name Server
10 IN PTR ns1.itzgeek.local.
;PTR Record IP address to HostName
100 IN PTR www.itzgeek.local.
150 IN PTR mail.itzgeek.local.
Check BIND Configuration Syntax
Use named-checkconf command to check the syntax of named.conf* files for any errors.
sudo named-checkconf
Command will return to the shell if there are no errors.
Also, you can use named-checkzone to check the syntax errors in zone files.
Forward Zone
sudo named-checkzone itzgeek.local /etc/bind/forward.itzgeek.local.db
Output:
zone itzgeek.local/IN: loaded serial 2 OK
Reverse Zone
sudo named-checkzone 0.168.192.in-addr.arpa /etc/bind/reverse.itzgeek.local.db
Output:
zone 0.168.192.in-addr.arpa/IN: loaded serial 2 OK
Restart bind service.
sudo systemctl restart bind9
Check the status of the bind9 service.
sudo systemctl status bind9
Verify DNS
Go to any client machine and add our new DNS server IP Address in /etc/resolv.conf file.
sudo nano /etc/resolv.conf
Make an entry like below.
nameserver 192.168.0.10
OR
Read the below tutorial to set DNS server IP in Linux.
READ: How to Set DNS IP address in CentOS / Fedora
READ: How to Set DNS IP address in Ubuntu / Debian – ifupdown
READ: How To Set DNS IP Address in Ubuntu 18.04 – Netplan
You can either use nslookup or dig command to verify the DNS server.
Use the dig command to verify the forward lookup.
dig www.itzgeek.local
If you get command not found, install bind-utils on Red Hat derivatives or dnsutils on the Debian derivatives package.
Output:
; <<>> DiG 9.11.5-P4-5.1-Debian <<>> www.itzgeek.local
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41979
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: c51856f159ddf40dadc13b835e1024a996e2a306d7888afe (good)
;; QUESTION SECTION:
;www.itzgeek.local. IN A
;; ANSWER SECTION:
www.itzgeek.local. 604800 IN A 192.168.0.100
;; AUTHORITY SECTION:
itzgeek.local. 604800 IN NS ns1.itzgeek.local.
;; ADDITIONAL SECTION:
ns1.itzgeek.local. 604800 IN A 192.168.0.10
;; Query time: 1 msec
;; SERVER: 192.168.0.10#53(192.168.0.10)
;; WHEN: Sat Jan 04 05:37:45 UTC 2020
;; MSG SIZE rcvd: 124
The DNS server’s answer for the forward lookup www.itzgeek.local is 192.168.0.100.
Confirm the reverse lookup with dig command.
dig -x 192.168.0.100
Output:
; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> -x 192.168.0.100
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33889
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 9806a5ee8f6645c178aa65b25e102530e49ae9a15456fbe1 (good)
;; QUESTION SECTION:
;100.0.168.192.in-addr.arpa. IN PTR
;; ANSWER SECTION:
100.0.168.192.in-addr.arpa. 604800 IN PTR www.itzgeek.local.
;; AUTHORITY SECTION:
0.168.192.in-addr.arpa. 604800 IN NS ns1.itzgeek.local.
;; ADDITIONAL SECTION:
ns1.itzgeek.local. 604800 IN A 192.168.0.10
;; Query time: 0 msec
;; SERVER: 192.168.0.10#53(192.168.0.10)
;; WHEN: Sat Jan 04 05:40:00 UTC 2020
;; MSG SIZE rcvd: 148
The DNS server’s answer for the reverse lookup 192.168.0.100 is www.itzgeek.local.
This result confirms that both forward and reverse zone lookups are working fine.
Conclusion
That’s All. You have successfully installed DNS server on Debian 10 / Debian 9. In our next article, we will configure the Slave DNS server on Debian 10 / Debian 9.