Point a company Internet domain to an Azure Traffic Manager domain
When you create a Traffic Manager profile, Azure automatically assigns a DNS name for that profile. To use a name from your DNS zone, create a CNAME DNS record that maps to the domain name of your Traffic Manager profile. You can find the Traffic Manager domain name in the General section on the Configuration page of the Traffic Manager profile.
For example, to point name www.contoso.com to the Traffic Manager DNS name contoso.trafficmanager.net, you would create the following DNS resource record:
www.contoso.com IN CNAME contoso.trafficmanager.net
All traffic requests to www.contoso.com get directed to contoso.trafficmanager.net.
You cannot point a second-level domain, such as contoso.com, to the Traffic Manager domain. DNS protocol standards do not allow CNAME records for second-level domain names.