• Supported Platforms
• M Series
• T Series

• Related Topics
• show interfaces (SONET/SDH) command in the Junos Interfaces Command Reference
• show interfaces statistics command in the Junos Interfaces Command Reference
• show policer command in the Junos Routing Protocols and Policies Command Reference

Configuring a Hierarchical Policer

The Enhanced IQ (IQE) PIC can police traffic at Layer 2 in a hierarchical manner. Hierarchical policing maintains two rates: an aggregate rate and a high-priority rate. The traffic is marked differently depending on class of service, currently expedited forwarding and nonexpedited forwarding. You can apply a hierarchical policer to incoming packets, outgoing packets, or both.

To configure a single-rate two-color policer:

1. Configure the forwarding classes.
   [edit class-of-service forwarding-classes]user@host# set class fc0 queue-num 0 priority high policing-priority premiumuser@host# set class fc1 queue-num 1 priority low policing-priority normaluser@host# set class fc2 queue-num 2 priority low policing-priority normaluser@host# set class fc3 queue-num 3 priority low policing-priority normal

   For the premium policer, the only configurable action is to discard the packet.

2. Configure the aggregate policer.
   [edit firewall policer policer1]user@host# set aggregate if-exceeding bandwidth-limit 100m burst-size-limit 20kuser@host# set aggregate then forwarding-class fc1

   The configurable actions are to discard the packet, change the loss priority, or change the forwarding class.

3. Configure the premium policer.
   [edit firewall policer policer1]user@host# set premium if-exceeding bandwidth-limit 200m burst-size-limit 50kuser@host# set premium then forwarding-class af

   For the premium policer, the only configurable action is to discard the packet.

4. Apply the policer to an interface.
   [edit interfaces so-1/0/0 unit 0]user@host# set layer2–policer input-hierarchical-policer policer1
5. Verify that the policer is working as expected.
   user@host> show interfaces so-0/0/0.0 detailuser@host> show interfaces so-0/0/0.0 statistics detailuser@host> show policer