Hello,

I need to know why Load Balancer (hardware or software) is must for Exchange server HA ?

I have gone thru few links but not able to understand why it i

Hello

tip:

if use nlb you only need one ip to manage. if add or remove cas server you not need additional settings only setup nlb and server use nlb address.
if have application server that use smtp to send email not need add cas servers ips and names to application only one ip and name.
if use hardware or windows nlb you can remove/stop cas server from nlb when need reboot  server and user not impact.

my question rather I would like to understand WHY Load Balancer is needed

Hi TheAtulA,
Exchange will not lad balance CAS servers by itself. Clients will connect to a single namespace which is pointed to VIP of 3rd party load balancer/NLB.

DAG is HA for mailbox servers. No HA for CAS servers without NLB or 3rd party software.
FYI CAS server is your client interface.

If you use DNS Roundrobin you can manage but it is not an automatic failover. A manual intervention is req

Exchange will not lad balance CAS servers by itself ?

do LOAD Balancer needed if there more than 2 CAS servers

If you are planning to have high availability for exchange you need software/hardware load balancer.

You have to load balance CAS servers