DNS concepts
What is a DNS zone?
A DNS zone represents a portion of the DNS namespace owned and managed as a single unit by one organization. The global DNS is composed of many zones.
Jeff Westhead
DNS zone delegation
Zone delegation is how a parent zone signals to DNS resolvers that authority for a child zone is served by a different set of servers.
Recursive vs Authoritative DNS — What's the difference?
There are two types of DNS servers: recursive and authoritative. Authoritative servers host DNS data, while recursive DNS servers perform DNS lookups for users.
All DNS record types
An overview of all the DNS record types. Each DNS record type is briefly explained, and extensive explanations are available in linked articles.
Ruurtjan Pul
DNS record types
The NS record
DNS NS records specify the authoritative name server for a domain. Learn how name server record works and how to configure them.
The CNAME record
DNS CNAME records are used to alias or redirect names in DNS. Learn how canonical names work in DNS, and what their restrictions are.
The MX record
The MX or “mail exchange” DNS record type is critical to the delivery of email via SMTP. MX records are used to specify a list of mail servers for a domain.
The TXT record
The TXT or “descriptive text” DNS record type was created to hold human-readable text but now plays a critical role in the prevention of spam on the Internet.
The A record
The A or “address” DNS record type maps DNS names to IPv4 addresses. Translating names to addresses is one of the most fundamental uses of the DNS.
The AAAA record
The AAAA DNS record type was created to hold IPv6 addresses. AAAA records, pronounced “quad A records” are similar to A records, but hold a 128-bit IPv6 address instead of a 32-bit IPv4 address.
The SOA record
DNS SOA records state that authority for a zone starts at a particular point in the tree of DNS names. Learn how they work and how they impact negative caching.
The SRV record
The SRV or "service locator" DNS record type enables service discovery in the DNS. SRV records allow services to be advertised on specific ports.
The PTR record
The PTR or "pointer" DNS record type maps an IP address to a domain name in the DNS. This is called a DNS reverse lookup.
Email and the DNS
SPF: A practical guide
Sender Policy Framework (SPF) records in the DNS identify the mail servers allowed to send email for a domain. SPF protects domains from email abuse.
DKIM: A practical guide
DomainKeys Identified Mail (DKIM) adds public key cryptography to email. Email is signed by the sender, and verified by the receiver using the DKIM record.
DMARC: A practical guide
Domain-based Message Authentication, Reporting, and Conformance (DMARC) is one of the three pillars of modern email security. It protects email senders and recipients from spoofing, spam, and phishing attacks.
MX vs SPF vs DMARC vs DKIM vs BIMI
Learn about the five DNS records that help control email delivery and spam prevention: MX, SPF, DKIM, DMARC, and BIMI.
How to merge DMARC records
DMARC protect domains from phishing and spam. A domain may have multiple senders for different types of email, but each domain may have only one DMARC record.
Using different DMARC records for subdomains
DMARC permits only one DMARC record per domain, but subdomains can be used when DMARC policies can't be merged.
Domain names
How does domain name registration work?
Domain registration is the process of making a new DNS zone available on the Internet.
10 tips for picking the perfect domain name
Your web address is as important as your brand. We've laid out 10 tips for you to pick the perfect domain name.
Holly Smith
Operations
The life of a DNS query in Kubernetes
In Kubernetes, DNS queries follow a specific path to resolve the IP address of a hostname. Here are all the steps and components it goes through.
Steven Reitsma
Security
What is the DNS Changer Malware?
The DNS changer malware changed the DNS servers of its victims. It was shut down by the FBI, Estonian police and NASA-OIG in 2011.
