Configuring QoS
Procedure
-
Configure how local priority values are assigned to ingress packets with the commands
qos cos-map
,qos dscp-map
, andqos trust
. -
If you do not want to use the default QoS profile to assign local priority values to ingress traffic, create one or more custom queue profiles with the command
qos queue-profile
. For each queue in a custom queue profile:- Assign a local priority value with the command
map queue
. - Optionally, define a descriptive name with the command
name queue
.
- Assign a local priority value with the command
-
If you do not want to use the default QoS schedule profile to determine the order in which queues are selected to transmit a packet, create one or more custom schedule profiles with the command
qos schedule-profile
. For each queue in a custom schedule queue profile, define scheduling priority with the commandsstrict queue
anddwrr queue
. -
Activate QoS settings with the command
apply qos
. This command lets you apply a queue profile and schedule profile globally to all interfaces, or a schedule profile override to individual interfaces. -
Optionally, add a rate limit for ingress traffic on one or more interfaces with the command
rate-limit
. -
View QoS configuration settings with the commands
show interface
,show qos cos-map
,show qos dscp-map
,show qos queue-profile
,show qos schedule-profile
, andshow qos trust
.
Examples
This example creates the following configuration:
- Configures CoS to be used to assign local priority to ingress packets.
Modifies the default CoS map to assign CoS 1 to local priority 1.
- Creates a queue profile named
Q1
and assigns local priorities as follows:Queue Local Priority 0 0 1 1 1 2 2 3 3 4 4 5 5 6 5 7 - Creates a schedule profile named
S1
and assigns DWRR to all queues in the schedule profile with the following weights:Queue Weight 0 5 1 10 2 15 3 20 4 25 5 50 Applies Q1 and S1 to all interfaces that do not have a QoS override applied.
switch(config)# qos trust cos switch(config)# qos cos-map 1 local-priority 1 switch(config)# qos queue-profile Q1 switch(config)# map queue 0 local-priority 0 switch(config)# map queue 1 local-priority 1 switch(config)# map queue 1 local-priority 2 switch(config)# map queue 2 local-priority 3 switch(config)# map queue 3 local-priority 4 switch(config)# map queue 4 local-priority 5 switch(config)# map queue 5 local-priority 6 switch(config)# map queue 5 local-priority 7 switch(config)# qos schedule-profile S1 switch(config)# dwrr queue 0 weight 5 switch(config)# dwrr queue 1 weight 10 switch(config)# dwrr queue 2 weight 15 switch(config)# dwrr queue 3 weight 20 switch(config)# dwrr queue 4 weight 25 switch(config)# dwrr queue 5 weight 50 switch(config)# apply qos queue-profile Q1 schedule-profile S1