What is the most likely cause of the problem?

A standalone wireless AP solution is being installed into the campus infrastructure. The access
points appear to boot correctly, but wireless clients are not obtaining correct access. You verify
that this is the local switch configuration connected to the access point:
interface ethernet 0/1
switchport access vlan 10
switchport mode access
spanning-tree portfast
mls qos trust dscp
What is the most likely cause of the problem?

A.
QoS trust should not be configured on a port attached to a standalone AP.

B.
QoS trust for switchport mode access should be defined as “cos”.

C.
switchport mode should be defined as “trunk” with respective QoS.

D.
switchport access vlan should be defined as “1”.

Explanation:
VLANs could be extended into a wireless LAN by adding IEEE 802.11Q tag awareness to the
access point. Frames destined for different VLANs are transmitted by the access point wirelessly
on different SSIDs with different WEP keys. Only the clients associated with that VLAN receive
those packets. Conversely, packets coming from a client associated with a certain VLAN are
802.11Q tagged before they are forwarded onto the wired network. If 802.1q is configured on the
FastEthernet interface of an access point, the access point always sends keepalives on VLAN1
even if VLAN 1 is not defined on the access point. As a result, the Ethernet switch connects to the
access point and generates a warning message. There is no loss of function on both the access
point and the switch. However, the switch log contains meaningless messages that may cause
more important messages to be wrapped and not be seen.
This behavior creates a problem when all SSIDs on an access point are associated to mobility
networks. If all SSIDs are associated to mobility networks, the Ethernet switch port the access

point is connected to can be configured as an access port. The access port is normally assigned
to the native VLAN of the access point, which is not necessarily VLAN1, which causes the
Ethernet switch to generate warning messages saying that traffic with an 802.1q tag is sent from
the access point.
Reference:
http://www.cisco.com/en/US/docs/wireless/access_point/12.4_10b_JA/configuration/guide/scg124
10b-chap14-vlan.html
http://www.cisco.com/en/US/docs/wireless/access_point/12.4_10b_JA/configuration/guide/scg124
10b-chap15-qos.html