Azure DNS and Private DNS Flashcards

Which Azure DNS record type is used to map a domain name to an Azure resource and automatically updates when the resource's IP changes?

Answer: Alias record

Azure DNS Alias records are aware of Azure resource lifecycle and automatically reflect IP changes for resources like Public IPs, Traffic Manager, and CDN.

What is the purpose of an Azure Private DNS Zone?

Answer: Provides name resolution for resources within Azure VNets without public DNS exposure

Azure Private DNS Zones provide DNS name resolution scoped to linked VNets, keeping records private and not resolvable from the internet.

How do you enable automatic DNS registration of VM hostnames in an Azure Private DNS Zone?

Answer: Enable 'auto-registration' when linking the VNet to the Private DNS Zone

Enabling auto-registration on the VNet link causes VMs in that VNet to automatically register their hostname and IP in the Private DNS Zone.

What is the maximum number of VNets you can link to a single Azure Private DNS Zone?

Answer: 1,000

Each Azure Private DNS Zone supports up to 1,000 virtual network links, with auto-registration enabled on up to 100 of them.

Which Azure service resolves Private DNS Zone names from on-premises networks connected via ExpressRoute or VPN?

Answer: Azure DNS Private Resolver with inbound/outbound endpoints

Azure DNS Private Resolver provides inbound endpoints that on-premises DNS servers can forward queries to for Private DNS Zone resolution.

When configuring a CNAME record in Azure DNS, which limitation applies at the zone apex (root domain)?

Answer: CNAMEs cannot be used at the zone apex — use an Alias record instead

DNS standards prohibit CNAME records at the zone apex (e.g., contoso.com); Azure DNS Alias records solve this for Azure resources.