1. [单选题]While troubleshooting a connectivity problem on the network, you issue the ping command from your PC command prompt, but the output shows "request times out."At which OSI layer is this problem associated with?
A. The data link layer
B. The application layer
C. The access layer
D. The session layer
E. The network layer
2. [单选题]Which type of cable should be used to make a connection between the Fa0/0 port on a router and the Fa0/0 port switch?
A. Rollover cable
B. Console cable
C. Crossover cable
D. Straight-through cable
E. Serial cable
3. [单选题]常见的LSA有几种类型()
A. 4
B. 5
C. 6
D. 7
