CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 271)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 271 of 350
DUT(config)# qos enable
Configure egress queue
Tail Drop
Tail drop is the default congestion-avoidance technique on every egress queue. With tail drop,
packets are queued until the thresholds are exceeded.
The following shows configuring tail drop threshold for different drop-precedence. Follow these
steps from Privileged Exec mode.
1. configure terminal.
2. interface IFNAME to specify the interface to match to the policy map.
IFNAME = name of interface
3. queue <0-7> threshold THRESHOLD1 THRESHOLD2 THRESHOLD3 to set threshold for
different drop-precedence.
THRESHOLD1 = threshold for drop-precedence 0. Range is 0-62
THRESHOLD2 = threshold for drop-precedence 1. Range is 1-63
THRESHOLD3 = threshold for drop-precedence 2. Range is 2-64
The following example shows configuring tail drop threshold for queue 3. In this example,
drop-precedence-0‘s threshold is 20, drop-precedence 1 is 30, drop-precedence 2 is 40.
DUT(config)# interface eth-0-1
DUT(config-if)# queue 3 threshold 20 30 40
WRED
WRED reduces the chances of tail drop by selectively dropping packets when the output
interface begins
to show signs of congestion. By dropping some packets early rather than waiting until the queue
is full, WRED avoids dropping large numbers of packets at once.
The following shows configuring WRED threshold for different drop-precedence. Follow these
steps from Privileged Exec mode.
1. configure terminal.
2. interface IFNAME to specify the interface to match to the policy map.
IFNAME = name of interface
3. queue <0-7> random-detect to set WRED mode.
4. queue <0-7> random-detect min-threshold MIN_THRESHOLD1 MIN_THRESHOLD2
MIN_THRESHOLD3 to set min threshold for different drop-precedence.
5. queue <0-7> random-detect max-threshold MAX_THRESHOLD1 MAX_THRESHOLD2
MAX_THRESHOLD3 to set max threshold for different drop-precedence.
6. queue <0-7> random-detect drop-probability DROP_PRO1 DROP_PRO2 DROP_PRO3 to
set drop probability for different drop-precedence.
The following example shows configuring WRED threshold for queue 1. In this example,
drop-precedence-0‘s min-threshold is 20, drop-precedence 1 is 30, drop-precedence 2 is 40, and