DNS RR is perfectly fine in a production environment.

Yes you need two public IPs or a load balancer.

A company that wants high availability but doesn’t want to invest in a load balancer has their priorities all wrong.

Yes there are free load balancers that are easy to find by searching Google or Bing.

Yes I have customers using DNS RR and it works fine. None of my customers use NLB because it is unsuitable for load balancing Exchange.

Since DNS RR is not really efficient in a production environment and you actually need two public IPs to make it work (provided you have two CAS box).

My question is, for an organisation that want their Mails to be highly available and don’t have enough to invest on an expensive load balancer. what will be your advice for this kind of people.

Secondly, are there any free efficient LB out there that you know of?

And also have you ever had/have a customer still using DNS RR or NLB for CAS HA and if yes what was your reaction?

Thanks.