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Quality of Service: Managing Bandwidth More Effectively
Globally-Configured QoS
Figure 5-23. Configuring and Displaying QoS Priorities for VLAN IDs
If you later decided to remove VLAN 20 from QoS prioritization, you would
enter the following command:
Figure 5-24. Returning a QoS-Prioritized VLAN to “No-override” Status
Assigning a DSCP Policy for a Global VLAN-ID Classifier
This global QoS packet-marking option assigns a previously configured DSCP
policy (codepoint and 802.1p priority) to outbound IP packets having the
specified VLAN-ID (VID). The switch:
1. Selects an incoming IP packet on the basis of the VLAN-ID it carries.
2. Overwrites the packet’s DSCP with the DSCP configured for matching
packets.
3. Assigns the 802.1p priority associated with the new DSCP. (See “Differen-
tiated Services Codepoint (DSCP) Mapping” on page 5-90.)
4. Forwards the packet through the appropriate outbound port queue.
HP Switch(config)# vlan 1 qos priority 2
HP Switch(config)# vlan 20 qos priority 5
HP Switch(config)# vlan 30 qos priority 5
HP Switch(config)# vlan 40 qos priority 7
HP Switch(config)# show qos vlan-priority
VLAN priorities
VLAN ID Apply rule | DSCP Priority
------- ----------- + ------ -----------
20 Priority | 5
20 Priority | 5
30 Priority | 5
40 Priority | 7
HP Switch(config)# no vlan 20 qos
HP Switch(config)# show qos vlan-priority
VLAN priorities
VLAN ID Apply rule | DSCP Priority
------- ----------- + ------ -----------
1 Priority | 2
20 No-override | No-override
30 Priority | 5
40 Priority | 7
In this instance, No- override
indicates that VLAN 20 is not
prioritized by QoS.