多项选择题
A.Classifying and marking traffic should be done as close to the traffic source as possible.
B.Classifying and marking traffic should be done at the distribution layer.
C.Traffic is classified and marked as it travels through the network.
D.If untrusted traffic enters a switch， it can be marked with a new QoS value appropriate for the policy in place.
E.The trust boundary moves depending on the type of traffic entering the network.
单项选择题 Refer to the exhibit. What problem is preventing users on VLAN 100 from pinging addresses on VLAN 200？（）
多项选择题 Cisco Express Forwarding has been enabled on router TK1. With CEF， prefixes that require exception processing can be cached with one of which four special adjacencies？ （）
多项选择题 Your boss， Miss ，is interested in CEF. What should you tell her？ （）