单项选择题 On corporate network, hosts on the same VLAN can communicate with each other, but they are unable to communicate with hosts on different VLANs. What is needed to allow communication between the VLANs?（）

单项选择题 Refer to the exhibit. What is the meaning of the output MTU 1500 bytes?（）

单项选择题 A cisco router is booting and has just completed the POST process.It is now ready to find and load an IOS image.what function does the router perform next?（）