802.1Q is a standard for VLAN tagging, which allows the network administrator to segment the network traffic of different departments into separate VLANs. This makes it easier to monitor and manage the traffic of each department.
Port mirroring is a feature that allows the network administrator to copy the traffic from one or more ports to another port for analysis. By configuring port mirroring on the ports connected to the specific department, the network administrator can monitor the traffic of that department in real-time.