1. [单选题]At which layer of the OSI model does the protocol that provides the information displayed by the "show cdp neighbors" command operate?
A. Transport
B. Physical
C. Application
D. Data link
E. Network
2. [单选题]路由器下“特权用户模式”的标识符是：()
A. >
B. !
C.
D. (config-if)
