The Company network is displayed in the following topology exhibit:
Workstation 1 traffic is set for cos 5 and the switch CompanyA sends workstation 1 traffic to
the switch CompanyB. However, not all of the traffic from Switch CompanyA is from
workstation 1.
Switch CompanyA configurations Switch CompanyB Configuration:
mls qos mls qos
interface fa0/1 interface fa0/1
switchport mode trunk switchport trunk mode
switchport trunk encapsulation dot 1q switchport trunk encapsulation dot 1q
switchport trunk native vlan 1 switchport trunk native vlan 1
Frames from Workstation 1 are given the rightful priority through Switch CompanyA, but
Switch CompanyB doesn’t reciprocate, and treats Workstation 1 frames as if they have no
precedence. Which of the following actions will prioritize traffic from Workstation 1?
A.
Configure qos all command under Switch CompanyB fa0/1 interface.
B.
Configure mls qos trust cos command under Switch CompanyB fa0/1 interface.
C.
Configure mls qos trust cos 5 command under Switch CompanyB fa0/1 interface.
D.
Configure qos cos 5 command under Switch CompanyB fa0/1 interface.
E.
Configure mls qos trust cos command under Switch CompanyA fa0/1 interface.
F.
Configure qos cos 5 command under Switch CompanyA fa0/1 interface.
Explanation:
The default action is for a switch with QoS features activated not to trust edge devices and
any frames that enter the switch have their CoS re-written to the lowest priority of zero. If the
edge device can be trusted, this default behaviour must be overridden and the access switch
must be configured to switch the frame, leaving the CoS bits untouched.
The trust is configured on the switch port using the command:
switch(config-if)#mls qos trust cos