DNS Based Load Balancers

Fri Jun 30 22:56:25 UTC 2006

I'm soliciting recommendations for DNS based load balancers.  
Currently, we have Cisco Global Site Selectors deployed buy have  
reached a limit for the number of active HTTP HEAD checks we can  
perform. This lack of scalability is restricting us severely with  
regards to the number of customers we can deploy for our product,  
which requires a separate HTTP HEAD check per IP per customer.

I am hoping to receive recommendations for devices which allow for  
DNS based load balancing (round robin and proximity based) as well as  
HTTP health checks (including content based health checks). It must  
be scalable to, at least, 2000 active checks and active answers.

I am currently investigating the Netscaler DNS offering as well as  
F5's 3DNS (or whatever they've changed the name to).