The Domain Name System (DNS) is essential for the Internet to work. Network administrators deal daily with DNS records. But DNS and its records can be hard to digest for new people in this business.
If you want to understand the functionality of the most common DNS records, here you have!
A or AAAA records
These two DNS records are in charge of linking a domain name with its corresponding IP address.
Both records have the same purpose. The difference is that A works with Internet Protocol version 4 (IPv4), while AAAA works with Internet Protocol version 6 (IPv6).
Now, you can see its relevance. Without these records, the DNS resolution process wouldn’t be possible. Remember that once a user requests a domain name, the translation from the domain name into its IP address is essential to load it.
Pointer (PTR) records point an IP address to a domain name. Yes, they work exactly in the opposite way the A and AAAA records do.
PTR records are a good ally of security. They are very used to prevent spam or legit e-mails from going to the spam folder. PTR records serve to verify that the IP addresses match the sender’s domain name they claim to be using. Without a PTR record, e-mails will not reach their destination. Servers will reject them.
Name server (NS) records are important because they point to the name server (or servers) of a domain name. NS records answer the DNS resolvers, where to look for a domain name’s IP address. A mistake while configuring these records can cause that the users won’t be able to resolve the domain.
Text (TXT) records are a useful tool for administrators to enter text messages or instructions into the DNS. This makes their work easier because the text is readable for them. Currently, it’s possible to add information in a machine “language” on this type of DNS record. They are used for many different tasks like verification of a service or a domain name, during the encryption process, or as a way for administrators to exchange messages.
Mail exchange (MX) records are key for you and your domain to receive e-mail messages properly. MX records must be set up to point out, whoever asks, the servers that accept incoming mail for a specific domain. This information is vital for e-mails to be routed accurately. Otherwise, the delivery of mail to your address will fail.
Start of authority (SOA) records are used to point out the corresponding authoritative name server for a domain name. They also have an administrative purpose since they have information related to the zone and the domain itself, like the refresh rate of both (updates), the time servers should wait for the next refresh, the contact of the domain’s administrator, etc.
To run an online business or manage a network will lead you directly to DNS. And DNS records will become tools for daily use. Better get familiar with them!