Service Manual

Displaying Default and Congured WRED Proles
To display the default and congured WRED proles, use the following command.
• Display default and congured WRED proles and their threshold values.
EXEC mode
show qos wred-profile
Displaying WRED Drop Statistics
To display WRED drop statistics, use the following command.
• Display the number of packets Dell Networking OS the WRED prole drops.
EXEC Privilege mode
show qos statistics wred-profile
Pre-Calculating Available QoS CAM Space
Before Dell Networking OS version 7.3.1, there was no way to measure the number of CAM entries a policy-map would consume (the
number of CAM entries that a rule uses is not predictable; from 1 to 16 entries might be used per rule depending upon its
complexity). Therefore, it was possible to apply to an interface a policy-map that requires more entries than are available. In this case,
the system writes as many entries as possible, and then generates an CAM-full error message (shown in the following example). The
partial policy-map conguration might cause unintentional system behavior.
%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3
Cam(PolicyQos) for class 2 (TeGi 12/20) entries on portpipe 1
The test cam-usage command allows you to verify that there are enough available CAM entries before applying a policy-map to
an interface so that you avoid exceeding the QoS CAM space and partial congurations. This command measures the size of the
specied policy-map and compares it to the available CAM space in a partition for a specied port-pipe.
Test the policy-map size against the CAM space for a specic port-pipe or all port-pipes using these commands:
• test cam-usage service-policy input policy-map {stack-unit } number port-set number
• test cam-usage service-policy input policy-map {stack-unit } all
The output of this command, shown in the following example, displays:
• The estimated number of CAM entries the policy-map will consume.
• Whether or not the policy-map can be applied.
• The number of interfaces in a port-pipe to which the policy-map can be applied.
Specically:
• Available CAM — the available number of CAM entries in the specied CAM partition for the specied line card or stack-unit
port-pipe.
• Estimated CAM — the estimated number of CAM entries that the policy will consume when it is applied to an interface.
• Status — indicates whether the specied policy-map can be completely applied to an interface in the port-pipe.
– Allowed — indicates that the policy-map can be applied because the estimated number of CAM entries is less or equal to
the available number of CAM entries. The number of interfaces in the port-pipe to which the policy-map can be applied is
given in parentheses.
– Exception — indicates that the number of CAM entries required to write the policy-map to the CAM is greater than the
number of available CAM entries, and therefore the policy-map cannot be applied to an interface in the specied port-pipe.
Quality of Service (QoS)
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