Exam 300-430 topic 1 question 21 discussion

When implementing QoS across a network that supports multiple VLANs and uses Cisco Access Points (APs) in local mode, the DSCP (Differentiated Services Code Point) trust model must be configured on the switch ports to which the APs are connected. Here’s why: DSCP Trust Model: DSCP is a Layer 3 QoS marking that provides granular traffic classification and prioritization. When the switch ports trust DSCP, they honor the DSCP values in the IP headers of packets, ensuring consistent QoS treatment across the network. This is particularly important in a multi-VLAN environment where traffic from different VLANs may have different QoS requirements. Local Mode APs: In local mode, APs forward all traffic to the Wireless LAN Controller (WLC), which applies QoS policies based on DSCP markings. By configuring the switch ports to trust DSCP, the switch ensures that the QoS markings are preserved as traffic travels between the APs and the WLC.

Because Local mode on AP, APs will terminate CAPWAP tunnel and AP will use DSCP marking of CAPWAP tunnel and convert it to UP value for 802.11 frame using DSCP to UP mapping, so C DSCP is correct

Cos markings only exist as a TAG within trunk packets. The question states that the access points are in local mode = access ports. There will therefore be no CoS markings on the packets between the access point and switch. Answer D. DSCP is correct as these markings are Layer3 and exist on both trunks and access ports.

это dscp

CAPWAP packets sent from local mode APs are UnTag packets.

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/voice-over-wireless-lan-vowlan/116056-technote-qos-00.html#:~:text=Switchports%20connected%20to%20local%20mode%20access%20points%20(APs)%20and%20Hybrid%20Remote%20Edge%20Access%20Point%20(H%2DREAP)/FlexConnect%20APs%20with%20no%20locally%20switching%20Wireless%20LANs%20(WLANs)%20should%20be%20access%20ports%20set%20with%20the%20mls%20qos%20trust%20dscp%20command. Answer is DSCP

When we use CoS, it is suppose to configure on trunk links and local switching. It makes sense with the option A.

Agree with kthekillerc

only option of trust mode is dscp

provided answer is correct. Switchports connected to local mode access points (APs) and Hybrid Remote Edge Access Point (H-REAP)/FlexConnect APs with no locally switching Wireless LANs (WLANs) should be access ports set with the mls qos trust dscp command. It could not be B as there is no such thing. 3 options for WMM are disabled, required, and allowed.

Answer is B.