Question : exchange 2010 CAS high availablity/ISA or harware load balancing

I have two 2 exchage 2010 client access servers runiing outlook web access. I need to deply a high availablity solution for these servers. When one CAS failes other should take over with out prompting for passsword and the trasition sould be trasparent to the user. I am using ISA 2006. Should I go for harware load blnacling or web farm ISA.

Answer : exchange 2010 CAS high availablity/ISA or harware load balancing

One way of making it with ISA server, depending your actual configuration of course. If ISA server has the external interface in the DMZ and a second interface in the internal network, and all your clients can reach this internal network, the same external publication can be configured for both external and internal interfaces. In this way your internal clients can point to your internal isa server interface, and the external ones to the DMZ interface

If it is not possible, your opcion is the HLB like say our friend busbar