Mirrored Ports and Observing Ports
Mirrored and observing ports have the following functions:
Mirrored ports are monitored ports. All the packets that pass through mirrored ports are copied and sent to observing ports.
Observing ports are connected to monitoring devices and send packets copied from mirrored ports to those monitoring devices.
An observing port is dedicated to forwarding mirrored traffic. Therefore, do not configure other services on an observing port; otherwise, mirrored traffic and other service traffic interfere with each other.
If the mirroring function is deployed on many ports of a device, a large amount of internal forwarding bandwidth will be occupied, which affects the forwarding of other services. Additionally, if the mirrored port bandwidth is higher than the observing port bandwidth, for example, 1000 Mbit/s on a mirrored port and 100 Mbit/s on an observing port, the observing port will fail to forward all mirrored packets in time because of insufficient bandwidth, leading to packet loss.
Mirroring Directions
Mirroring directions define whether the packets to be copied to observing ports are those entering or leaving (or both) mirrored ports:
Inbound
The switch copies packets received by mirrored ports and sends them to observing ports.
Outbound
The switch copies packets sent from mirrored ports and sends them to observing ports.
Bidirectional
The switch copies packets received and sent by mirrored ports and sends them to observing ports.