Cisco Catalyst 4500 Series - How to Implement Policing

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 44 Configuring Quality of Service
Configuring QoS on a Standalone Supervisor Engine 6-E/6L-E or Supervisor Engine 7-E/7L-E/8-E
– 10K Input Policers and 6K Output Policers
– 12K Input Policers and 4K Output Policers
– 14K Input Policers and 2K Output Policers
– 16K Input Policers and 0 Output Policers
These numbers represent individual policer entries in the hardware that support a single rate and burst
parameter. Based on this, a switch supports the following number of policers:
• 16K Single Rate Policer with Single Burst (Two Color Marker)
• 8K Single Rate Three Color Marker (srTCM)
• 8K Two Rate Three Color Marker (trTCM)
These policers are partitioned between Input and Output in chunks of 2K policer banks. The different
types of policers can all co-exist in the system. However, a given type of policer (srTCM, trTCM etc.) is
configurable as a block of 128 policers.
Note Two policers are reserved for internal use.
How to Implement Policing
For details on how to implement the policing features on a Catalyst 4500 Series Switch, refer to the
Cisco IOS documentation at the following link:
http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfpolsh.html
Platform Restrictions
Platform restrictions include the following:
• Multi-policer actions can be specified (setting CoS and IP DSCP is supported).
• When unconditional marking and policer based marking exists on the same field(cos or dscp or
precedence), policer-based marking is preferred.
• If policer based service-policy is attached to both a port and a VLAN, port-based policed is preferred
by default. To over-ride a specific VLAN policy on a given port, then you must configure a per-port
per-vlan policy.
• You should not delete a port-channel with a per-port, per-VLAN QoS policy.
Workaround: Before deleting the port-channel, do the following:
1. Remove any per-port per-VLAN QoS policies, if any.
2. Remove the VLAN configuration on the port-channel with the no vlan-range command.
Marking Network Traffic
Marking network traffic allows you to set or modify the attributes of traffic (that is, packets) belonging
to a specific class or category. When used in conjunction with network traffic classification, marking
network traffic is the foundation for enabling many quality of service (QoS) features on your network
This module contains conceptual information and the configuration tasks for marking network traffic.