DNS Records Explained: A, PTR, CNAME, NS, MX, SOA, TXT

February 19, 2022

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3 min read

In this video, I go over the different DNS record types and how to use them with practical examples. I go over the most common DNS record types including A, PTR, CNAME, NS, MX, SOA, and TXT records.

– A Record, A means address record. The forward zone file uses A record. A record associates a subdomain with a certain IP address.

– PTR record, found in the Reverse zone file. It’s known as a reverse lookup, and it’s most commonly used to verify the hostname of a mail server. If we search for a subdomain that is related to an IP, it will seek for the PTR record in the reverse zone and identify the IP associated with the subdomain.

– CNAME Record, CNAME stands for canonical name, and it is used to define each host record to point to the original A record if we wish to use the same server for different subdomains. This is referred to as aliasing.

– NS Record, NS records defines the Name Server or DNS server of the domain, if we want to know any domains DNS server, then we have to query the NS record.

– MX record, MX trans for mail exchanger, the domains mail server is specified by the MX record. MX record defined with its priority, if domains have multiple mail servers then we can set them with priority.

– SOA record, SOA trans for the start of authority. SOA contains administrative information about the zone, like responsible contact person for the zone, last update time, zone transfer timing to secondary DNS etc.

– TXT record, TXT records associates arbitrary text data with the zone, these records are for a special purpose, like for mail server security SPF, DKIM and DMARC records are provided in DNS as TXT record, sometimes special codes are provided as TXT record for domain verification by various organizations.

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Linux DNS Server Configurations
Install and Configure Linux DNS Server: https://youtu.be/FeZjRF-aVlc
Primary DNS Or Master DNS Server Configuration: https://youtu.be/fb41xuax8xU
Secondary DNS Or Slave DNS Server Configuration: https://youtu.be/jygerYi-Ytk
Caching DNS Server Configuration: https://youtu.be/y_PUUwY0vwc
DNS Forwarder Configuration with Caching DNS: https://youtu.be/nDJ8WsXYtMs
Forward Zone Configuration For DNS Forward Lookup: https://youtu.be/4ghXAJvI-t4
Reverse DNS Configuration For DNS Reverse Lookup: https://youtu.be/ButSB33dXtA
DNS Records A, PTR, CNAME, NS, MX, SOA, TXT: https://youtu.be/tpQReHosCD4