Flow-based services improve the switch's ability to have better control over the traffic by providing a generic framework for the Match and Set features. Incoming packets are classified according to match rules using fields from L2-L4 headers, and defined actions are taken accordingly. Examples include QoS remarking and policing, monitoring using SPAN, sFlow, and Forwarding such as PBR, L2 redirect.
Flow-based monitoring conserves bandwidth by only inspecting specified traffic instead of inspecting all interface traffic. Flow-based tracking allows you to monitor only the traffic that is received by the source port, and that matches criteria in the ingress access-lists (ACLs). IPv4 ACLs, IPv6 ACLs, and MAC ACLs support flow-based monitoring.