Azure DNS

What it is

Azure DNS is a hosted authoritative DNS service for public name resolution. You create DNS zones for domains you own (e.g. contoso.com), add records (A, AAAA, CNAME, MX, TXT, etc.), and Azure answers queries globally using Microsoft’s anycast name servers.

Why it exists

Instead of running your own BIND/DNS servers or paying a registrar for resolution, you need high-availability, low-latency, global DNS with a clean management UI/API. Azure DNS keeps management inside your Azure portal/ARM pipeline and integrates with other Azure resources.

Key ideas

• DNS zone — the container for a domain; name servers (NS) are assigned to each zone (typically 4).
• Record sets — group records of the same type + name; alias records (can point to Azure resources like LBs, Front Door, blobs, or other zones; track resource IP changes automatically — no manual updates).
• TTL on records; delegation — point your registrar’s NS to Azure’s zone NS.
• Private DNS — separate service for internal resolution; see private-dns.
• Considerations: use alias records to reference Azure Service endpoints; CNAME/alias disallow certain combos; DNS resolution latency via global anycast.

How it fits

[registrar] ─NS─► [Azure DNS zone: contoso.com]──A/www→ 20.x.x.x (LB/Front Door)
                        record sets: A, CNAME, MX, TXT, alias

Exam notes

• Alias records avoid IP churn when target Azure resources change — key for [LOAD BALANCER] front-door consistency.
• Azure DNS = public authoritative; Azure Private DNS = internal (linked to VNets). Know the distinction.
• Record set types + TTL are common asked details.
• You can move DNS hosting of a domain to Azure by delegating NS records.

Related

Home · private-dns · vnet · load-balancer · azure-front-door

📘 Source: Microsoft Learn — Azure Dns