A rule indicates that data having particular characteristics be automatically routed to a particular destination. When software on a switching device detects a new data stream, it is analyzed to determine whether it has characteristics specified by the rule. If it does, the packet is encapsulated with a special tag, indicating that the packet should be routed to the new destination. Also, an entry is added to a quick-lookup table in the switching device. The entry indicates that future packets in the data stream that have the same source and destination port and address should also be routed to the new destination.