Question 1

What are DNS records?

Accepted Answer

DNS records are entries in the Domain Name System that map domain names to IP addresses and other information. Common types include A (IPv4), AAAA (IPv6), MX (mail servers), TXT (text data like SPF/DKIM/DMARC), NS (name servers), SOA (zone authority), CNAME (aliases), and CAA (certificate authority authorization).

Question 2

What is an MX record?

Accepted Answer

An MX (Mail Exchange) record specifies which mail servers accept email for your domain and in what priority order. Lower priority numbers indicate preferred servers. MX records are essential for email delivery.

Question 3

What is a TXT record used for?

Accepted Answer

TXT records store arbitrary text data and are commonly used for email authentication (SPF, DKIM, DMARC), domain ownership verification (Google, Microsoft, Facebook), and security policies (MTA-STS, TLS-RPT).

Question 4

What is reverse DNS (PTR) and FCrDNS?

Accepted Answer

Reverse DNS (PTR record) maps an IP address back to a hostname. Forward-Confirmed reverse DNS (FCrDNS) verifies that the PTR hostname resolves back to the original IP. This is critical for email deliverability — mail servers check FCrDNS to detect spoofing.

Question 5

How long do DNS changes take to propagate?

Accepted Answer

DNS propagation depends on the TTL (Time To Live) of each record. Changes can take from a few minutes to 48 hours to propagate worldwide. Lowering TTL before making changes can speed up propagation.

Question 6

What is a CAA record?

Accepted Answer

CAA (Certificate Authority Authorization) records specify which certificate authorities are allowed to issue SSL/TLS certificates for your domain. This helps prevent unauthorized certificate issuance and improves security.