Az104 — Azure DNS

· Azure DNS is a hosting service for DNS domains that provides name resolution by using Microsoft Azure infrastructure.

o DNS uses a global directory hosted on servers around the world.

o Microsoft is part of that network that provides a DNS service through Azure DNS.

o A DNS server is also known as a DNS name server, or just a name server.

· The configuration information for your DNS server is stored as a file within a zone on your DNS server.

· Each file is called a record.

· The following record types are the most commonly created and used:

• A is the host record, and is the most common type of DNS record.
• It maps the domain or host name to the IP address.
• CNAME is the canonical name, or the alias for an A record. If you had different domain names that all accessed the same website, you would use CNAME.
• MX is the mail exchange record.
• It maps mail requests to your mail server, whether hosted on-premises or in the cloud.
• TXT is the text record.
• It’s used to associate text strings with a domain name.
• Azure and Microsoft 365 use TXT records to verify domain ownership.
• CAA (certificate authority)
• NS (name server)
• SOA (start of authority)
• SPF (sender policy framework)
• SRV (server locations)

· The SOA and NS records are created automatically when you create a DNS zone by using Azure DNS.

· To publish a private DNS zone to your virtual network, you specify the list of virtual networks that are allowed to resolve records within the zone.

· Private DNS zones have the following benefits:

• There’s no need to invest in a DNS solution.
• DNS zones are supported as part of the Azure infrastructure.
• All DNS record types are supported: A, CNAME, TXT, MX, SOA, AAAA, PTR, and SVR.
• Host names for VMs in your virtual network are automatically maintained.
• Split-horizon DNS support allows the same domain name to exist in both private and public zones.
• It resolves to the correct one based on the originating request location.

· If you check the DNS zone for wideworldimports.com, you’ll see there are two apex domain records:

· NS and SOA.

o The NS and SOA records are automatically created when you created the DNS zone.

· Azure alias records enable a zone apex domain to reference other Azure resources from the DNS zone.

· You don’t need to create complex redirection policies.

· You can also use an Azure alias to route all traffic through Traffic Manager.

· The Azure alias record can point to the following Azure resources:

• A Traffic Manager profile
• Azure Content Delivery Network endpoints
• A public IP resource
• A front door profile

· The alias record set supports the following DNS zone record types:

• A: The IPv4 domain name-mapping record.
• AAAA: The IPv6 domain name-mapping record.
• CNAME: The alias for your domain, and links to the A record.

· Application Insights, a feature of Azure Monitor, is an extensible Application Performance Management (APM) service for developers and DevOps professionals.

· It monitors live web applications and you can enable it for many Azure App Service web apps without modifying any of the app’s code.

· Application Insights also works for apps on a wide variety of platforms including .NET, Node.js, Java, and Python hosted on-premises, hybrid, or any public cloud.