Administrator Guide

In cases such as these, where class-maps with overlapping ACL rules are applied to dierent 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 ows may have several match criteria. All ows 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 ows in the class-map.
The ow-based DSCP marking feature allows you to assign dierent DSCP to each match criteria.
• Create matching ows within a class map that have dierent 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 specied value.
Example of Marking Flows in the Same Queue with Dierent 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 Congured Class Maps and Match Criteria
To display all class-maps or a specic 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 trac classication. In the following example, trac is classied in
two Queues, 1 and 2. Class-map ClassAF1 is “match any,” and ClassAF2 is “match all”.
• Display all class-maps or a specic class map.
EXEC Privilege mode
show qos class-map
Examples of Trac Classications
The following example shows incorrect trac classications.
Dell#show running-config policy-map-input
!
policy-map-input PolicyMapIn
service-queue 1 class-map ClassAF1 qos-policy QosPolicyIn-1
service-queue 2 class-map ClassAF2 qos-policy QosPolicyIn-2
Quality of Service (QoS)
637