You design an Azure web application. The web application is accessible by default as a standard
cloudapp.net URL.
You need to recommend a DNS resource record type that will allow you to configure access to the
web application by using a custom domain name.
Which DNS record type should you recommend?

A.
SRV

B.
MX

C.
CNAME

D.
A

Explanation:
A CNAME record maps a specific domain, such as contoso.com or www.contoso.com, to a canonical
domain name. In this case, the canonical domain name is the <myapp>.cloudapp.net domain name
of your Azure hosted application. Once created, the CNAME creates an alias for the
<myapp>.cloudapp.net. The CNAME entry will resolve to the IP address of your
<myapp>.cloudapp.net service automatically, so if the IP address of the cloud service changes, you
do not have to take any action.
Incorrect:
Not D:
* Since an A record is mapped to a static IP address, it cannot automatically resolve changes to the IP
address of your Cloud Service.
* An A record maps a domain, such as contoso.com or www.contoso.com, or a wildcard domain such
as *.contoso.com, to an IP address. In the case of an Azure Cloud Service, the virtual IP of the
service. So the main benefit of an A record over a CNAME record is that you can have one entry that
uses a wildcard, such as *.contoso.com, which would handle requests for multiple sub-domains such
as mail.contoso.com, login.contoso.com, or www.contso.com.
Configuring a custom domain name for an Azure cloud service
http://azure.microsoft.com/en-gb/documentation/articles/cloud-services-custom-domain-name/