In cases such as these, where class-maps with overlapping ACL rules are applied to different queues, use
the keyword order. The Dell Networking OS writes to the CAM ACL rules with lower order numbers
(order numbers closer to 0) before rules with higher order numbers so that packets are matched as you
intended.
• Specify the order in which you want to apply ACL rules using the keyword order.
order
The order can range from 0 to 254.
By default, all ACL rules have an order of 255.
Setting DSCP Values for Egress Packets Based on Flow
Match-any Layer 3 flows may have several match criteria. All flows that match at least one of the match
criteria are mapped to the same queue because they are in the same class map.
Setting a DSCP value from QOS-POLICY-IN mode (refer to Setting a DSCP Value for Egress Packets)
assigns the same DSCP value to all of the matching flows in the class-map.
The flow-based DSCP marking feature allows you to assign different DSCP to each match criteria.
• Create matching flows within a class map that have different DSCP values.
CLASS MAP mode
match set-ip-dscp
The values you set from CLASS-MAP mode override the value you set in the QoS input policy DSCP
value. Packets matching the rule are marked with the specified value.
Example of Marking Flows in the Same Queue with Different DSCP Values
Dell#show run class-map
!
class-map match-any example-flowbased-dscp
match ip access-group test set-ip-dscp 2
match ip access-group test1 set-ip-dscp 4
match ip precedence 7 set-ip-dscp 1
Dell#show run qos-policy-input
!
qos-policy-input flowbased
set ip-dscp 3
Displaying Configured Class Maps and Match Criteria
To display all class-maps or a specific class map, use the following command.
Dell Networking OS Behavior: An explicit “deny any" rule in a Layer 3 ACL used in a (match any or match
all) class-map creates a "default to Queue 0" entry in the CAM, which causes unintended traffic
classification. In the following example, traffic is classified in two Queues, 1 and 2. Class-map ClassAF1 is
“match any,” and ClassAF2 is “match all”.
• Display all class-maps or a specific class map.
EXEC Privilege mode
show qos class-map
734 Quality of Service (QoS)