## Configure the BlackBerry Administration Service instances in the pool to communicate across network subnets

The instances in the BlackBerry® Administration Service pool use multicast UDP to communicate with each other. If the BlackBerry Administration Service instances are in different network subnets and your organization's network configuration does not permit multicast UDP across the network subnets, you must configure the BlackBerry Administration Service instances to use TCP to communicate with each other. For example, if your organization uses a UDP peer-to-peer firewall filter, you must configure the BlackBerry Administration Service instances to communicate across network subnets.