Based on the network shown in the graphic which option contains the potential networking problem and protocol or setting that can to prevent the problem?（）

单项选择题Which command can be used from a PC to verify the connectivity between hosts that connect through a switch in the same LAN?（）

A.ping address
B.tracert address
C.traceroute address
D.arp address

多项选择题Which two benefits are provided by creating VLANs? （）

A.added security
B.dedicated bandwidth
C.provides segmentation
D.allows switches to route traffic between subinterfaces
E.contains collisions

单项选择题Refer to the exhibit. Which statement is true?（）

A.The Fa0/11 role confirms that SwitchA is the root bridge for VLAN 20.
B.VLAN 20 is running the Per VLAN Spanning Tree Protocol.
C.The MAC address of the root bridge is 0017.596d.1580.
D.SwitchA is not the root bridge, because not all of the interface roles are designated.

单项选择题What dose a Layer 2 switch use to decide where to forward a received frame?（）

A.source MAC address
B.source IP address
C.source switch port
D.destination IP address
E.destination port address
F.destination MAC address

单项选择题At which layer of the OSI model is RSTP used to prevent loops?（）

A.data link
B.network
C.physical
D.transport