What are two errors in this policy-map configuration? (Choose two.)
policy-map test
class voice
priority 64
class bulk
bandwidth percent 20
fair-queue
class interactive
bandwidth percent remaining 10
fair-queue
class class-default
fair-queue
A.
The bandwidth command is missing for the class-default traffic class.
B.
WFQ cannot be configured for the class-default traffic class.
C.
WFQ cannot be configured for the bulk and interactive traffic classes.
D.
The bandwidth units for the bulk and interactive traffic classes are inconsistent.
E.
The priority command cannot be used with the bandwidth command within the same policy-map.
F.
The voice traffic class should have the no fair-queue command.
Explanation:
Weighted Fair Queuing (WFQ) classifies traffic entering the queue based on traffic flows. The actual classification can be based on source and destination addresses, the protocol and TCP port numbers. Each flow is given its own queue. In its simplest form WFQ services each of these queues on a round robin basis. This means that every flow of traffic has an equal share of the available bandwidth, if it is required. Hence the term "fair" queue. The benefit for low volume traffic is reduced and predictable latency. For many applications this default behavior of WFQ is sufficient, however, some applications need specific QoS guarantees that require more than simply "fair" access to the bandwidth. In this case, the "weight" needs to be modified so that WFQ does not share bandwidth on a round-robin basis, but is influenced by the class or priority of the traffic in the flow.
Weighted fair queuing is activated on an interface using the fair-queue command:Router(config)# interface serial 0/0 Router(config-if)# fair-queue