To add a DNS server, specify General Information and click Check Connectivity. Once you are connected successfully, only then you can add a DNS server. BIND DNS server is the designated DNS server for the Linux category.

Click Add Server & Configure. Specify required information for DNS Server.

General Settings

• DNS Server Type: HC supports BIND DNS server for its Linux platform.
• Act as Secondary: Enabling the option makes the server act as a secondary DNS.
• Conf File Path: All the settings for the BIND name server itself are stored in the named.conf file. This field indicates the location path for the file, which usually is /etc/named.conf.
• DNS PID File Path: It is a quoted string and allows to define where the PID (Process Identifier) used by BIND is written. PID's full path usually is /var/run/named.pid.
• Chroot Environment: Enabling the checkbox allows BIND to run in a chroot jail. Any process running in a chroot jail is simply unable to see any part of the filesystem or access resources, outside the jail. It's done with security in mind.
• Primary Name Server: This is the primary DNS server. It holds the master copy of all zones over which it has authority e.g. ns1.domain.com.
• Secondary Name Server: This is the secondary DNS server. It obtains it resource records from the primary name server. It serves as the next DNS server in line, if the primary DNS goes offline, making DNS always available. The secondary DNS looks somewhat like ns2.domain.com.

Custom Settings

HC lets you add various DNS records through its interface. These give the settings for the DNS records. 

• A (Host Record): An A record (Address Record) points a domain or subdomain to an IP address. For example domain.com can be pointed to 192.168.1.12, so that when the end user types in the easily recognizable domain name (domain.com) it gets pointed to the IP.   
• AAAA (Host Record): An AAAA record is the same as an A record, but it allows you to point a domain to an IPv6 address instead of an IPv4 address.
• CNAME (Name Alias Record): CNAME points one domain or subdomain to another domain name, allowing you to update only one A record each time you make a change, without needing to change all the records that need pointing to the IP. For example www.domain.com can be pointed to domain.com. Now if the end user types in www.domain.com, it will be directed to domain.com.
• MX (Mail Exchange Record): An MX record routes email to a particular mail server. It shows the mail server that handles a domain's email. In simple words it tells the world which mail servers accept incoming mail for a domain. It contains the host name of the mail server and a priority code. The priority is used when more than one MX records are entered for any single domain name. This happens when more than one mail servers are configured. The priority identifies which mail server should be preferred. The mail server with the lower number has higher priority. For example in:

domain.com.                           IN MX 10 mail.domain.com.
domain.com.                           IN MX 15 domain.com. 

The mail server with number 10 has higher priority. The server with the higher number (15) will be contacted only if the server with lower number is unavailable. MX entries always point to a domain and never point directly to an IP address. The domain must map directly to one or more address records (A, or AAAA) in the DNS, and must not point to any CNAME records.

• TXT (Text Data Record): The TXT record isn’t used to direct any traffic but instead to provide information to outside sources. These records are used to store text-based information related to your domain. The TXT record can be used for various purposes. TXT records can be used for:
  
  • Verification of domain ownership
  • Sender Policy Framework
  • DomainKeys (DKIM)

TXT records usually contain a lot of text and unlike other DNS records, the record can contain spaces and various special characters. For example 

domain.com.                           IN        TXT     "v=spf1 a mx ptr ~all"

• SRV (Service Record): An SRV record is used to identify computers that host specific services such as VOIP or IM. For instance an SRV record can be used in Internet Telephony to define where a SIP service may be found.
• CAA: CAA record specifies which certificate authorities (CAs) are allowed to issue SSL/TLS certificates for a domain.

The following table provides a sample of all the supported DNS records and their data: