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Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 41 Configuring PFC QoS
Configuring PFC QoS
Configuring 1q4t/2q2t Tail-Drop Threshold Percentages
On
1q4t/2q2t
ports, the receive- and transmit-queue drop thresholds have this relationship:
•
Receive queue 1 (standard) threshold 1 = transmit queue 1 (standard low priority) threshold 1
•
Receive queue 1 (standard) threshold 2 = transmit queue 1 (standard low priority) threshold 2
•
Receive queue 1 (standard) threshold 3 = transmit queue 2 (standard high priority) threshold 1
•
Receive queue 1 (standard) threshold 4 = transmit queue 2 (standard high priority) threshold 2
To configure tail-drop threshold percentages for the standard receive and transmit queues on
1q4t
/
2q2t
LAN ports, perform this task:
When configuring the receive- and transmit-queue tail-drop thresholds, note the following information:
•
You must use the transmit queue and threshold numbers.
•
The
queue_id
is 1 for the standard low-priority queue and 2 for the standard high-priority queue.
•
The percentages range from 1 to 100. A value of 10 indicates a threshold when the buffer is
10-percent full.
•
Always set threshold 2 to 100 percent.
•
Ethernet and Fast Ethernet
1q4t
ports do not support receive-queue tail-drop thresholds.
This example shows how to configure receive queue 1/threshold 1 and transmit queue 1/threshold 1 for
Gigabit Ethernet port 2/1:
Router#
configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
interface gigabitethernet 2/1
Router(config-if)#
wrr-queue threshold 1 60 100
Router(config-if)#
end
Router#
This example shows how to verify the configuration:
Router#
show queueing interface gigabitethernet 2/1
Transmit queues [type = 2q2t]:
<...Output Truncated...>
queue tail-drop-thresholds
--------------------------
1 60[1] 100[2]
2 40[1] 100[2]
Command
Purpose
Step 1
Router(config)#
interface
{
ethernet
|
fastethernet
|
gigabitethernet
}
slot/port
Selects the interface to configure.
Step 2
Router(config-if)#
wrr-queue threshold
queue_id
thr1% thr2%
Configures the receive- and transmit-queue tail-drop
thresholds.
Router(config-if)#
no wrr-queue threshold
[
queue_id
]
Reverts to the default receive- and transmit-queue
tail-drop thresholds.
Step 3
Router(config-if)#
end
Exits configuration mode.
Step 4
Router# show queueing interface {
ethernet
|
fastethernet
|
gigabitethernet
}
slot/port
Verifies the configuration.