down, the bypass switch immediately switches into bypass- mode. Some manufacturers of bypass TAPs/switches still send traffic to the appliance during bypass mode. When the link comes back up again, the bypass switch returns to bypass-off normal. Some bypass switches send a heartbeat packet through the monitoring appliance in order to ensure that the appliance is passing traffic. If the heartbeat packet does not return to the bypass switch, the appliance is assumed to be down, and the switch goes into bypass-on mode, excluding the appliance from the traffic path. The bypass switch continues to transmit heartbeat packets to the appliance, and when they are again returned by the appliance, the bypass switch changes back to bypass-off mode and the appliance resumes receiving traffic.... Whenever the bypass switch transitions to bypass mode for any reason, the link may be temporarily dropped. A good bypass switch reconnects the link in under 1 second, but the network may take several seconds to re-establish communications on link. Device management Bypass switches may be managed through any of several interfaces: a command-line interface (CLI), a Web browser-based interface, or a platform-based SNMP tool. Management functions may include configuring an IP address for SNMP traps, retrieving RMON statistics, and setting parameters for the heartbeat packet such as packet contents, timing, and retry counts. References See also Intrusion-prevention system Network intrusion detection system Computer network security