350-501 · Question #326
Refer to the exhibit. A network engineer configures CPE-1 for QoS with these requirements: - IPv4 and IPv6 traffic originated by the CPE-1 WAN IP address must be marked with DSCP CS3. - IPv4 LAN…
The correct answer is A. class-map match-any SELF_TRAFFIC. The engineer must implement a class-map to classify various traffic types for QoS marking. Using match-any allows the class-map to include distinct traffic flows that each need specific QoS treatment later.
Question
Refer to the exhibit. A network engineer configures CPE-1 for QoS with these requirements:
- IPv4 and IPv6 traffic originated by the CPE-1 WAN IP address must be
marked with DSCP CS3.
- IPv4 LAN traffic must be marked with DSCP CS1.
- IPv6 LAN traffic must be marked with DSCP default.
Which configuration must the engineer implement on CPE-1?
Exhibit
Options
- Aclass-map match-any SELF_TRAFFIC
- Bclass-map match-all SELF_TRAFFIC
- Cclass-map match-all SELF_TRAFFIC
- Dclass-map match-any SELF_TRAFFIC
How the community answered
(67 responses)- A73% (49)
- B3% (2)
- C16% (11)
- D7% (5)
Why each option
The engineer must implement a class-map to classify various traffic types for QoS marking. Using `match-any` allows the class-map to include distinct traffic flows that each need specific QoS treatment later.
The `class-map match-any` command correctly identifies traffic belonging to any of the specified access-groups (`FROM_SELF`, `FROM_LAN_V4`, `FROM_LAN_V6`). This is essential because the requirements specify distinct traffic types (self-originated IPv4/IPv6, LAN IPv4, LAN IPv6) that will likely receive different QoS markings, and `match-any` ensures all these relevant flows are aggregated for processing.
The `match-all` keyword would require traffic to simultaneously match all three access-groups, which is not applicable for classifying distinct types of traffic that originate from different sources or have different characteristics.
This configuration only includes the `FROM_SELF` traffic and fails to classify the IPv4 LAN traffic and IPv6 LAN traffic as required.
This configuration includes `FROM_SELF` and `FROM_LAN_V4` traffic but fails to include the `FROM_LAN_V6` traffic as required.
Concept tested: QoS traffic classification with class-maps
Source: https://www.cisco.com/c/en/us/td/docs/ios/qos/configuration/guide/qos_c/qc_classify_traffic_psa.html#wp1010376
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