In an Ethernet network, under what two scenarios can devices transmit? （）

多项选择题Which of the following are benefits of VLANs? （）

A.They increase the size of collision domains.
B.They allow logical grouping of users by function.
C.They can enhance network security.
D.They increase the size of broadcast domains while decreasing the number of collision domains.
E.They increase the number of broadcast domains while decreasing the size of the broadcast domains.
F.They simplify switch administration.

多项选择题What are three benefits of implementing vlans?（）

A.A more efficient use of bandwidth can be achieved allowing many physical groups to use the same network infrastructure
B.Broadcast storms can be mitigated by decreasing the number of broadcast domains,thus increasing their size.
C.A higher level of network security can be reached by separating sensitive data traffic from other network traffic.
D.Port-based vlans increase switch-port use efficient,thanks to 802.1Q trunks
E.A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure.
F.Broadcast storms can be mitigated by increasing the number of broadcast domains,thus reducing their size.
G.VLANs make it easier for IT staff to configure new logical groups,because the vlans all belong to the same broadcast domain.

单项选择题A switch is configured with all ports assigned to vlan 2 with full duplex FastEthernet to segment existing departmental traffic. What is the effect of adding switch ports to a new VLAN on the switch?（）

A.More collision domains will be created.
B.IP address utilization will be more efficient.
C.More bandwidth will be required than was needed previously.
D.An additional broadcast domain will be created.

单项选择题Which switch would STP choose to become the root bridge in the selection process?（）

A.32768: 11-22-33-44-55-66
B.32768: 22-33-44-55-66-77
C.32769: 11-22-33-44-55-65
D.32769: 22-33-44-55-66-78

多项选择题Which two protocols are used by bridges and or switches to prevent loops in a layer 2 network? （）

A.802.1d
B.VTP
C.802.1q
D.STP
E.SAP