Cisco Systems 4500 Queue Allocation Failure

37-83
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 37 Configuring Quality of Service Configuring QoS on Supervisor Engine 6-E, Supervisor Engine 6L-E, Catalyst 4900M, and Catalyst 4948E
Queue Allocation Failure
The switch might not be able to meet the explicit queue size required on one or more queues on an
interface because of fragmentation of queue memory or lack of enough free reserve entries. In this
scenario, the switch logs an error message to notify you of the failure. The QoS service policy is left
configured on the interface. You can fix the error by removing the QoS service policy and examining the
current use of the queue entries from the free reserve by other ports on the switch.
To configure class-level queue-limit in a service policy, perform this task:
To remove the explicit queue size use the no queue-limit command under the class in a policy map.
Command Purpose
Step 1 Switch# configure terminal Enters global configuration mode.
Step 2 Switch(config)# policy-map
policy-map-name Creates a policy map by entering the policy-map name, and enters
policy-map configuration mode.
By default, no policy maps are defined.
Step 3 Switch(config-pmap)# class class-name Specifies the name of the class whose traffic policy you want to
create or change, and enters policy-map class configuration mode.
By default, no traffic classes are defined.
Step 4 Switch(config-pmap-class)# shape
average {cir-bps kbps | percent
percent}
Enables average-rate traffic shaping.
You can specify the bandwidth in kbps or as a percentage:
• For cir-bps, specify the committed information rate, the bit rate
that traffic is shaped to, in bps. The range is 32000 to
10000000000 bps.
• For percent, specify the percentage of link rate to shape the class
of traffic. The range is 1 to 100.
By default, average-rate traffic shaping is disabled.
Step 5 Switch(config-pmap-class)# queue-limit
number-of-packets Provides an explicit queue size in packets. The size must be a
multiple of eight and ranging from 16 to 8184.
Step 6 Switch(config-pmap-class)# exit Returns to policy-map configuration mode.
Step 7 Switch(config-pmap)# exit Returns to global configuration mode.
Step 8 Switch(config)# interface interface-id Specifies a physical port and enter interface configuration mode.
Step 9 Switch(config-interface)#
service-policy output policy-map-name Specifies the policy-map name, and apply it a physical interface.
Step 10 Switch(config-interface)# end Returns to privileged EXEC mode.
Step 11 Switch# show policy-map
[policy-map-name [class
class-map-name]]
or
Switch# show policy-map interface
interface-id
Verifies your entries.
Step 12 Switch# copy running-config
startup-config (Optional) Saves your entries in the configuration file.