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Applying DSCP and VLAN Match Criteria on a Service Queue
You can configure Layer 3 class maps which contain both a Layer 3 Differentiated Services Code Point (DSCP) and IP VLAN IDs
as match criteria to filter incoming packets on a service queue on the switch.
To configure a Layer 3 class map to classify traffic according to both an IP VLAN ID and DSCP value, use the match ip vlan
vlan-id command in class-map input configuration mode. You can include the class map in a policy map, and apply the class
and policy map to a service queue using the service-queue command. In this way, the system applies the match criteria in a
class map according to queue priority (queue numbers closer to 0 have a lower priority).
To configure IP VLAN and DSCP match criteria in a Layer 3 class map, and apply the class and policy maps to a service queue:
1. Create a match-any or a match-all Layer 3 class map, depending on whether you want the packets to meet all or any of
the match criteria. By default, a Layer 3 class map is created if you do not enter the layer2 option with the class-map
command. When you create a class map, you enter the class-map configuration mode.
CONFIGURATION mode
Dell(conf)#class-map match-all pp_classmap
2. Configure a DSCP value as a match criterion.
CLASS-MAP mode
Dell(conf-class-map)#match ipdscp 5
3. Configure an IP VLAN ID as a match criterion.
CLASS-MAP mode
Dell(conf-class-map)#match ip vlan 5
4. Create a QoS input policy.
CONFIGURATION mode
Dell(conf)#qos-policy-input pp_qospolicy
5. Configure the DSCP value to be set on matched packets.
QOS-POLICY-IN mode
Dell(conf-qos-policy-in)#set ip-dscp 5
6. Create an input policy map.
CONFIGURATION mode
Dell(conf)#policy-map-input pp_policmap
7. Create a service queue to associate the class map and QoS policy map.
POLICY-MAP mode
Dell(conf-policy-map-in)#service-queue 0 class-map pp_classmap qos-policy pp_qospolicy
Enabling Buffer Statistics Tracking
You can enable the tracking of statistical values of buffer spaces at a global level. The buffer statistics tracking utility operates
in the max use count mode that enables the collection of maximum values of counters.
To configure the buffer statistics tracking utility, perform the following step:
1. Enable the buffer statistics tracking utility and enter the Buffer Statistics Snapshot configuration mode.
CONFIGURATION mode
DellEMC(conf)#buffer-stats-snapshot
DellEMC(conf)#no disable
Enable this utility to be able to configure the parameters for buffer statistics tracking. By default, buffer statistics tracking is
disabled.
2. Enable the buffer statistics tracking utility and enter the Buffer Statistics Snapshot configuration mode.
CONFIGURATION mode
DellEMC(conf)#buffer-stats-snapshot
DellEMC(conf)#no disable
Quality of Service (QoS)
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