i have an Azure web app and I give it a custom domain name like (www.mysite.com), then i change the custom domain name to the name (www.subdomin.mysite.com), the problem i can not reach the first domain name (www.mysite.com) it gives the following:
404 Web Site not found.
You may be seeing this error due to one of the reasons listed below :
Custom domain has not been configured inside Azure. See how to map an existing domain to resolve this.
Client cache is still pointing the domain to old IP address. Clear the cache by running the command ipconfig/flushdns.