Which command is used to enable EtherChannel hashing for Layer 3 IP and Layer 4 port-based CEF？（）

单项选择题Refer to the exhibit. In the diagram， the switches are running IEEE 802.1s MST. Which ports are in the MST blocking state？（）

A. GE-1/2 and GE 2/1
B. GE-1/1 and GE-2/2
C. GE-3/2 and GE 4/1
D. no ports are in the blocking state
E. There is not enough information to determine which ports are in the blocking state.

单项选择题WhichstatementistrueaboutTCNpropagation？（）

A.The originator of the TCN immediately floods this information through the network.
B.The TCN propagation is a two step process.
C.A TCN is generated and sent to the root bridge.
D.The root bridge must flood this information throughout the network.

单项选择题Refer to the exhibit. Catalyst R is the root bridge for both VLAN 1 and VLAN 2.What is the easiest way to load-share traffic across both trunks and maintain redundancy in case a link fails，without using any type of EtherChannel link-bundling？（）

A. Increase the root bridge priority （increasing the numerical priority number） for VLAN 2 on Catalyst D so that port D2 becomes the root port on Catalyst D for VLAN 2.
B. Decrease the port priority on R2 for VLAN 2 on Catalyst R so that port D1 will be blocked for VLAN 2 and port D2 will remain blocked for VLAN 1.
C. Decrease the path cost on R2 on Catalyst R for VLAN 2 so that port D1 will be blocked for VLAN 2 and port D2 will remain blocked for VLAN 1.
D. Increase the root bridge priority （decreasing the numerical priority number） for VLAN 2 on Catalyst R so that R2 becomes the root port on Catalyst D for VLAN 2.

单项选择题Whichstatementistrueaboutloopguard？（）

A.Loop guard only operates on interfaces that are considered point-to-point by the spanning tree.
B.Loop guard only operates on root ports.
C.Loop guard only operates on designated ports.
D.Loop guard only operates on edge ports.

单项选择题WhywouldaroguehostthatisrunningaDHCPserveronacampusLANnetworkpresentasecurityrisk？（）

A.It may allocate IP addresses from an unknown subnet to the users.
B.All multicast traffic can be sniffed by using the DHCP multicast capabilities.
C.The CPU utilization of the first hop router can be overloaded by exploiting DHCP relay open ports.
D.A potential man-in-the-middle attack can be used against the clients.