Classification Based On Qos Acls - Cisco IE 3000 Software Configuration Manual

Understanding QoS
Figure 32-3 Classification Flowchart
Is a policer configured
Check if the packet is in
profile by querying the policer.

Classification Based on QoS ACLs

You can use IP standard, IP extended, or Layer 2 MAC ACLs to define a group of packets with the same
characteristics (class). In the QoS context, the permit and deny actions in the access control entries
(ACEs) have different meanings than with security ACLs:
•
•
•
•
When creating an access list, remember that, by default, the end of the access list contains an implicit
Note
deny statement for everything if it did not find a match before reaching the end.
Cisco IE 3000 Switch Software Configuration Guide
32-6
Start
Get the clasification
result for the packet.
for this packet?
Yes
Yes
Pass
through
Check out-of-profile action
configured for this policer.
Modify DSCP according to the
policed-DSCP map. Generate
Done
If a match with a permit action is encountered (first-match principle), the specified QoS-related
action is taken.
If a match with a deny action is encountered, the ACL being processed is skipped, and the next ACL
is processed.
If no match with a permit action is encountered and all the ACEs have been examined, no QoS
processing occurs on the packet, and the switch offers best-effort service to the packet.
If multiple ACLs are configured on a port, the lookup stops after the packet matches the first ACL
with a permit action, and QoS processing begins.
No
No
Drop
Mark
a new QoS label.
Chapter 32 Configuring QoS
Drop packet.
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