Introduction to traffic mirroring
Traffic mirroring copies the specified packets to the specified destination for packet analyzing and monitoring. It is implemented through QoS policies. In other words, you define traffic classes and configure match criteria to classify packets to be mirrored and then configure traffic behaviors to mirror packets that fit the match criteria to the specified destination. Traffic mirroring allows you to flexibly classify packets by defining match criteria and obtain accurate statistics.
You can configure the traffic to be mirrored to an interface, to a CPU, or to a VLAN.
Mirroring traffic to an interface copies the matching packets to a destination interface.
Mirroring traffic to a CPU copies the matching packets to a CPU (the CPU of the device where ports with traffic mirroring configured reside).
For more information about QoS policies, traffic classes, and traffic behaviors, see ACL and QoS Configuration Guide.