Configure Barracuda Load Balancer with Exchange 2010

Question

I have following scenario:
1 x DB
1 x Exchange multi role server on VLAN1 on site 1
1 x Exchange multi role Server on VLAN2 on site 2
1 x cas array on site 1
1 x cas array on site 2
1 x Barracuda at site 1.
How barracuda will load balance my 2 exchange servers located on different subnets and sites? Do i need to make them SINGLE SITE? and make them part of single array or i can do it without bringing them into single site. Barracuda can access both exchange servers.
I cannot move servers, all i have to do is in the same scenario and that is to load balance CAS services.
Hasan

Answer 1

If your network supports(i.e. Bandwidth between Vlan1 and Vlan2) and if it is single ADsite you can. You have to add both Vlan1 server and Vlan2  server to the load balancer. 
Enable DAC on both servers http://technet.microsoft.com/en-us/library/dd979790(v=exchg.150).aspx
Cconfigure alternatewitness on DAG properties. http://technet.microsoft.com/en-us/library/dd297934(v=exchg.150).aspx
One server with all roles in Vlan1  IP 192.168.1.101  
One server with all roles in Vlan2  IP 192.168.2.101
Assume you configured 192.168.1.100 as Barracuda VIP and pointed the names to this IP.
If your Vlan1 network goes down your Exchange will go offline till you point the CAS Array FQDN to the IP of the Vlan2 server in Vlan2 DNS server. (i.e point CAS array FQDN to 192.168.2.101 as per above example)
If you are not sure about the configuration on Barracuda I suggest you take help from Barracuda support to configure as per the above scenario. 
If you want to reduce the traffic between Vlans you can switchoff shadow redundancy. Please read about
shadow redundancy before switching off
Set-TransportConfig -ShadowRedundancyEnabled $false
Thanks, MAS
Please mark as helpful if you find my comment helpful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.
I got you. Now if i make both Vlans server part of single array and that array FQDN IP will obviously be one of VLANs IP, so if that VLAN goes down then i need to change the IP of CAS array FQDN from local DNS (Pick one IP from another VLAN) and also on
Barracuda... right? 
Also correct me that VLAN IP on Barracuda will be the IP of CAS Array FQDN right? 
Hasan