Exchange 2013 CAS HA with KEMP in less than 5 minutes

Yes you can setup your High Available CAS 2013 in less than 5 minutes if you have already done stuff on the exchange side. Let me tell you where it took most time for me to setup the Exchange 2013 CAS HA starting with my lab setup

My lab environment (built on MS hyper-v)

-1 Windows 2008 R2 DC
-2 Exchange 2013 CAS Servers
-1 Exchange 2013 Mailbox Server
-Domain setup as CAFÉ.CORP

Exchange 2013 CAS does not need to have a Layer 7 load balancer so it can be load balanced on the Layer 4. Below diagram shows how the setup was done for the Layer 4.

Kemp VLM Dashboard
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cas lb
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In the above picture-Do not get confused in the above picture with this Layer7 option; enabling it is a requirement to enable SNAT, which is a recommendation for Exchange 2013. Also make sure “L7 Transparency” is not checked.


Click image for the full size image

Here you can see the real server’s ip address which are CAS 2013 servers. Add them one by one.

That’s it – You are done with configuring the Exchange 2013 High Available CAS Server.


The image below shows that your both server are up and being load balanced.


 Didn’t I tell you it takes less than 5 minutes to setup A High Available Exchange CAS 2013 🙂



OWA is showing the VIP in the above picture



Things to remember and mistakes to avoid otherwise it can take hours to troubleshoot

-Takeout pen and paper and design your lab
-Note down the VIP
-Add DNS entry for the VIP e.g. mail.owa.corp point to while the real server ip 192.168.36 and for CAS1 and CAS2 respectively
-Point your autodiscover to the VIP
-Test both CAS server locally to make sure they are working
– All servers should be pingable and also the VIP


Last very important thing to remember while setting up the virtual NIC on the hypervisor makes sure you select the proper NIC for the VMs otherwise you will end up troubleshooting enormous hour. I thank for this to Bhargav who helped me figured this out.