Priority Commands
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each queue before moving on to the next queue. Thus, a queue weighted 8
will be allowed to transmit up to 8 packets, after which the next lower priority
queue will be serviced according to it’s weighting. This prevents the
head-of-line blocking that can occur with strict priority queuing. When
configured for hybrid priority queuing mode, the switch will always employ
strict priority queuing for the highest priority queue (queue 3), before
processing queues 2 through 0 according to their WRR weights.
Example
The following example sets the queue mode to strict priority service mode:
switchport priority default
This command sets a priority for incoming untagged frames. Use the no form to
restore the default value.
Syntax
switchport priority default default-priority-id
no switchport priority default
default-priority-id - The priority number for untagged ingress traffic.
The priority is a number from 0 to 7. Seven is the highest priority.
Default Setting
The priority is not set, and the default value for untagged frames received on
the interface is zero.
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• The precedence for priority mapping is IP DSCP, and default switchport
priority.
• The default priority applies for an untagged frame received on a port set to
accept all frame types (i.e, receives both untagged and tagged frames). This
priority does not apply to IEEE 802.1Q VLAN tagged frames. If the incoming
frame is an IEEE 802.1Q VLAN tagged frame, the IEEE 802.1p User Priority
bits will be used.
• This switch provides eight priority queues for each port. It is configured to use
Weighted Round Robin, which can be viewed with the show queue
bandwidth command. Inbound frames that do not have VLAN tags are
tagged with the input port’s default ingress user priority, and then placed in the
appropriate priority queue at the output port. The default priority for all ingress
Console(config)#queue mode strict
Console(config)#
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