DNS Apex Record and Content Delivery Networks (CDN)
If you’ve moved to the cloud for your mission critical applications, your CDN provider has replicated your systems and distributed the cloned websites across multiple data centers. A “welcome to our CDN service” email will likely instruct you to get started by routing traffic to their CDN load balancer named cdn-loadblancer@someCDNcompany.com and you’re all set.
For standard DNS A records like www.example.com, this is not a problem. When you add a www.host Cname record that points to cdn-loadblancer@someCDNcompany.com, an end user’s request for www.example.com will hit the CDN’s load balancer and everything just works without a problem.
But new Internet usage trends – spawned by both end users and even your marketing department – look to simplify web browsing and content delivery by eliminating the “www” host name and enabling just the URL (e.g. example.com). But how does this work with CDNs, when your users do not want/need to see cdn-loadbalancer@someCDNcompany.com? After all, having a CNAME at the apex record is deemed illegal as defined by the DNS RFC.
UltraDNS enables this functionality with Apex Alias. With Apex Alias, you simply point example.com to cdn-loadbalncer@someCDNcompany.com and then let UltraDNS and your CDN provider do the rest of the work to direct and distribute your end users across the CDN data centers. UltraDNS will chase the DNS recursive resolution to conclusion and return the IP address of the destination webserver located somewhere in the CDN service. One DNS query; one final DNS response; one happy DNS system administrator.