Quality of Service (QoS): Managing Bandwidth More Effectively
Using QoS Classifiers To Configure QoS for Outbound Traffic
QoS VLAN-ID (VID) Priority
QoS Classifier Precedence: 5
The QoS VLAN-ID option supports up to 120 VLAN IDs (VIDs) as QoS
classifiers, depending on rule use by other QoS options.
Where a particular VLAN-ID classifier has the highest precedence in the switch
for traffic in that VLAN, then traffic received in that VLAN is marked with the
VID classifier’s configured priority level. Different VLAN-ID classifiers can
have differing priority levels.
Options for Assigning Priority. Priority control options for packets
carrying a specified VLAN-ID include:
■ 802.1p priority
■ DSCP policy (Assigning a new DSCP and an associated 802.1p priority;
inbound packets must be IPv4.)
(For operation when other QoS classifiers apply to the same traffic, refer to
“Classifiers for Prioritizing Outbound Packets” on page 6-9.)
Note QoS with VID priority applies to static VLANs only, and applying QoS to
dynamic VLANs created by GVRP operation is not supported. A VLAN must
exist while a subject of a QoS configuration, and eliminating a VLAN from the
switch causes the switch to clear any QoS features configured for that VID.
Assigning a Priority Based on VLAN-ID
This option assigns a priority to all outbound packets having the specified
VLAN-ID (VID). You can configure this option by either specifying the VLAN-
ID ahead of the qos command or moving to the VLAN context for the VLAN
you want to configure for priority.
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