I have a currently deployed IC6500 which I will be clustering with a second IC6500, but have not yet located any info on what the current OAC users should expect. Will they be notified that they need to pull down an update with the new IC information, as they are when the IC6500 is upgraded?
The default behavior is for the client to get a message saying an upgrade is required. You can disable this on the IC6500 if needed. However, it should continue to work with the old version of OAC.
An upgrade prompt of some sort was what I wondered about, but wasn't sure. By turning off the upgrade possibility, it would continue to communicate with the original IC, but wouldn't necessarily see the newly clustered IC, correct? It will need to pull down the secondary server ip info, and/or the new cluster name in the upgrade to gain that?
It should be able to see the cluster... no need to upgrade. Just don't stay too far with version differences. I've had OAC on older version communciating with IC cluster on new versions.
I assume you will have both IC devices in the cluster at the same firmware.
Assuming that you are creating an active/passive IC cluster, there will be a Virtual IP address which must be used by all of the devices on the network so that if an event occurs which initiates a node-flip, the devices will still be able to communicate with an IC.
The endpoints will not be automatically populated with this new information though, you will need to either push a settings update file or, force the users to login to an agent-realm which is configured to install the Agent that is configured with the new settings.
We strongly advise against running OAC agents which are of lower build than the IC. Although most functionality will not be affected, I've seen instances where ipSec tunnels would not initiate due to the version discrepancy along with some other "strange behaviors".
That being said, you can certainly disable the "Upgrade Notification" that the users would see by browsing to Maintenance -> System -> Options and then unchecking the box for "Enable automatic upgrade of UAC Agents"
I hope this addresses your concerns.