Use Step 1 or Step 2 to start creating a Layer 2 class map.1 Create a match-any class map.CONFIGURATION modeclass-map match-any2 Create a match-all class map.CONFIGURATION modeclass-map match-all3 Specify your match criteria.CLASS MAP modematch macAfter you create a class-map, Dell Networking OS places you in CLASS MAP mode.Match-any class maps allow up to five access-lists. Match-all class-maps allow only one. You can match against only one VLAN ID.4 Link the class-map to a queue.POLICY MAP modeservice-queueDetermining the Order in Which ACLs are Used to Classify TrafficWhen you link class-maps to queues using the service-queue command, Dell Networking OS matches the class-maps according toqueue priority (queue numbers closer to 0 have lower priorities).For example, as described in the previous example, class-map cmap2 is matched against ingress packets before cmap1.ACLs acl1 and acl2 have overlapping rules because the address range 20.1.1.0/24 is within 20.0.0.0/8. Therefore (without the keywordorder), packets within the range 20.1.1.0/24 match positive against cmap1 and are buffered in queue 7, though you intended for thesepackets to match positive against cmap2 and be buffered in queue 4.In cases such as these, where class-maps with overlapping ACL rules are applied to different queues, use the keyword order. DellNetworking OS writes to the CAM ACL rules with lower order numbers (order numbers closer to 0) before rules with higher order numbersso that packets are matched as you intended.• Specify the order in which you want to apply ACL rules using the keyword order.orderThe order can range from 0 to 254.By default, all ACL rules have an order of 255.Displaying Configured Class Maps and Match CriteriaTo 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 "defaultto Queue 0" entry in the CAM, which causes unintended traffic classification. In the following example, traffic is classified in two Queues, 1and 2. Class-map ClassAF1 is “match any,” and ClassAF2 is “match all”.• Display all class-maps or a specific class map.EXEC Privilege modeshow qos class-mapQuality of Service (QoS) 737
