Refer to the exhibit． Hosts on the same VLAN can communicate with each other but are unable to communicate with hosts on different VLANs． What is needed to allow communication between VLANs?

A、 a switch with a trunk link that is configured between the switches
B、 a router with an IP address on the physical interface that is connected to the switch
C、 a switch with an access link that is configured between the switches
D、 a router with subinterfaces configured on the physical interface that is connected to the switch

【正确答案】 D

【答案解析】同一交换机上的不同VLAN间的通讯，必须借助与三层的接口，我们可以在交换机上接一个路由器，利用路由器的子接口和交换机之间做trunk，这样来实现连通性。