4-152 Sun Fire B1600 Blade System Chassis Switch Administration Guide •June 2003
Command Usage
■The precedence for priority mapping is IP Precedence or 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 are used.
■This switch provides four priority queues for each port. It is configured to use
Weighted Round Robin, which can viewed with the 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 ports is
zero. Therefore, any inbound frames that do not have priority tags are placed
in queue 0 of the output port. (Note that if the output port is an untagged
member of the associated VLAN, these frames are stripped of all VLAN tags
prior to transmission.)
Example
The following example shows how to set a default priority on port SNP3 to 5:
4.3.15.2 queue bandwidth
Use this command to assign weighted round-robin (WRR) weights to the four class-
of-service (COS) priority queues. Use the no form to restore the default weights.
Syntax
queue bandwidth weight1...weight4
no queue bandwidth
weight1...weight4 – The ratio of weights for queues 0 to 3 determines the
weights used by the WRR scheduler. (Range: 1-255)
Default Setting
Weights 16, 64, 128 and 240 areassigned to queue 0, 1, 2 and 3 respectively.
Console(config)#interface ethernet SNP3
Console (config-if)#switchport priority default 5