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The LARK has interfaces on both the front and the rear of the appliance, each serving a specific role. This page describes those roles. The physical mix of interfaces on the rear, which varies between appliances, is covered on the interface configurations page.

Front interfaces

The front of the appliance holds the BMC/NIC component, which combines the baseboard management controller (BMC) with a network interface card (NIC). It exposes two kinds of interface:

BMC Management Port

The BMC’s dedicated out-of-band management interface. It supports system-level access independent of the operating system and is used during configuration and troubleshooting, including reaching the IPMI to monitor the appliance during boot.

Data Offloading Ports (NIC)

The copper interfaces on the NIC, used primarily for data offloading. They are not part of the traffic capture path.
The BMC Management Port and the NIC data offloading ports serve different purposes. The BMC Management Port is used for hardware-level administration of the appliance; the NIC ports are used for exporting collected data. Data offloading is covered in the data management section.

Rear interfaces

The rear panel carries the interfaces used for day-to-day operation: connecting to the appliance and feeding it traffic to monitor. Two roles are served.

Connectivity

One or more rear RJ45 interfaces connect the appliance to the equipment through which it is accessed, typically a switch, or a laptop connected directly. These interfaces carry management traffic between the laptop and the appliance’s tools. The available methods are described on the connection methods page.

TAP Ingress Port

One rear interface is the TAP Ingress Port, used exclusively for ingesting traffic to be monitored. A copy of live traffic, delivered from a TAP or a switch SPAN (mirror) port, enters through this interface and is passed to the appliance’s sensors. Because the appliance receives only a copy, it never sits inline and never affects the traffic it observes.
The TAP Ingress Port is used exclusively for incoming traffic to be monitored. It must not be used for connectivity or data offloading. Feeding traffic to the wrong interface prevents the appliance from observing the intended traffic.
The rear panel provides a mix of fiber (SFP+) and copper (RJ45) interfaces; the exact combination depends on the appliance’s configuration. The interface configurations page describes the available combinations and identifies which interface serves as the TAP Ingress Port in each case.