Types of policy actions

The policy actions are broadly classified in the following categories:
  • Remark actions

  • Police actions

  • Other actions

Each policy entry can have a combination of policy actions from these multiple categories, which are executed in the order of configuration.

Remark actions

This category contains the following actions:
  • Priority Code Point (PCP): 3-bit field in layer 2 802.1Q header refers to a class of service and maps to a frame priority level.

  • IP precedence: 3-bit field in IP header which denotes the importance or priority of the datagram.

  • IP Differentiated Services Code Point (DSCP): 6-bit field in IP header for packet classification.

  • Local Priority: Change the internal priority used to queue the packets for transmission. Local priority can be used to rewrite the priority of traffic classes local to the system based on the QoS mapping settings without changing the IP header or the 802.1Q header. Remark actions other than local priority only change packets as they leave the switch. The local priority action can be combined with the other remark actions to remark packets and change the internal priority to reflect the new priority.

Police actions

Traffic policing meters inbound traffic on an interface or VLAN based on the following traffic parameters:
  • Committed information rate (CIR): Bandwidth limit for guaranteed traffic.

  • Committed burst size (CBS): Maximum packet size permitted for bursts of data that exceed the CIR.

Based on these parameters, packets are dropped when traffic exceeds the bandwidth limit (CIR) and the burst size for guaranteed traffic (CBS).

Other actions

Other actions include Drop: Drop the packet, and Mirror: Mirror the packets to a specified mirroring session. For details, see the Monitoring Guide.