DNS Round Robin: We have 2 SA4000 IVEs in different geographical locations. Each physical IVE has different external IPs. Our external DNS host entry (host.domain.com) has both devices' IPs associated with it. DNS by nature should alternate between the addresses, so every other request should be directed to a different IVE. This has worked well for us. We see a 55% to 45% load balance between the IVEs. We use IE to initiate\authenticate sessions. If an IVE is unavailable and it is the IVE that DNS directs the request to, IE will attempt the request again. The next time, the request should be directed to the other address. The sign-on page may take a few seconds longer to load because of the time it takes IE to make the second request, but we've never had anyone complain since connectivity is always available. Cluster: We have a true IVE Active\Active cluster. They are not stand-alone. So, session information spans both IVEs.
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