Radius Account Server Redundancy

In our environment we use the Radius Accounting to forward information to agents that pass that to our firewall to automate access through the Firewall by the user logged in. For redundancy we have multiple agents. Unfortunately, I have to shutdown all but one agent or the result is unpredictable and some users information will not be available to the firewall. I would love the ability to forward the Accounting information to multiple agents simultaneously (as opposed to Load Balanced or 1st available) so that all agents would always have all the information.