Asynchronous network interface and method of synchronization between two applications on different computers is provided. The network interface contains snooping hardware which can be programmed to contain triggering values comprising either addresses, address ranges or other data which are to be matched. These data are termed “trip wires”. Once programmed, the interface monitors the data stream, including address data, passing through the interface for addresses and data which match the trip wires which have been set. On a match, the snooping hardware can generate interrupts, increment event counters, or perform some other application-specified action. This snooping hardware is preferably based upon Content-Addressable Memory.The invention thus provides in-band synchronization by using synchronization primitives which are programmable by user level applications, while still delivering high bandwidth and low latency. The programming of the synchronization primitives can be made by the sending and receiving applications independently of each other and no synchronization information is required to traverse the network.