CCNA真题(1)TCP/IP：地址和协议2

21: Your organization is using the 192.168.1.0/24 address space. You need 28 subnets. What subnet mask would you use to create these subnets?
B. 255.255.255.128
D. 255.255.255.224
F. 255.255.255.248
22: Which of the following protocols maps IP addresses to MAC addresses for connectivity to occur between two hosts?
B. RARP
D. DHCP
23: Your junior network administrator cannot seem to ping a host in another network and asks you why it isn't working. Which of the following is not an answer that you would give him?
B. The destination host is not powered on.
D. The IP address of the switch to which the destination host connects is incorrect.

A. Class A
C. Class C

A. It represents the number of hosts possible on that subnetwork.
C. It represents the class of IP address being used.