global server load balancing with the domain name

[Chuck Swiger]

On Apr 14, 2017, at 2:40 PM, McDonald, Daniel (Dan) <Dan.McDonald at austinenergy.com> wrote:
> Setting up global server load balancing seems easy enough – just add ns records pointing at the load balancer and away you go:
>  
> example.com.     38400    IN            SOA        ns20.example.net. dan\.mcdonald.example.com. 2017011107 10800 3600 604800 3600
> example.com.     38400    IN            NS           ns1.example.com.
> example.com.     38400    IN            NS           ns2.example.com.
> test.example.com.             900         IN            NS           gslb1.example.com.
> test.example.com.             900         IN            NS           gslb2.example.com.

Are your load-balancers providing different DNS replies to different clients?

Most organizations don't need to place the nameservers themselves behind a LB.

> That works fine for test.example.com.  But when I go to production, I need to do it for example.com and www.example.com.  How do I delegate just the A record and not the SOA, TXT, MX, SPF, and NS records, nor any of the other entries in the zone.  As I recall, I can’t just delegate , as an example,  www.example.com, then use a CNAME for example.com.

You can't delegate individual records-- you delegate zones.

If you had multiple DCs available, you might use a CNAME to point www.example.com to www.dc1.example.com, www.dc2.example.com, etc based upon whatever criteria seems reasonable, such as availability, client geolocation data, etc.  For web traffic, it is common to set a session cookie or similar for session affinity to keep requests going to the same DC once a given client has landed there.

You might want to have a chat with someone from Akamai, Level3, or one of the other CDN players.

Regards,
-- 
-Chuck