Answers to Assessment Test

1. A, C, E. To define a Class A address, the first bit in the first byte must be a zero. The range is 1 to 126, and the first octet represents the entire network portion of the address. See Chapter 2 for more information.
2. C. The command line console 0 places you at a prompt where you can then set your console user-mode password. See Chapter 4 for more information.
3. A. 256 − 192 = 64. 64 + 64 = 128. 128 + 64 = 192. The subnet is 128, the broadcast address is 191, and the valid host range is the numbers in between, or 129–190. See Chapter 3 for more information.
4. B. The passive command, short for passive-interface, stops regular updates from being sent out of an interface. However, the interface can still receive updates. See Chapter 6 for more information.
5. C. Internet Control Message Protocol (ICMP) is the protocol at the Network layer that is used to send echo requests and replies. See Chapter 2 for more information.
6. D. Layer 2 switching creates individual collision domains. See Chapter 7 for more information.
7. C. The command line vty 0 4 places you in a prompt that will allow you to set or change your Telnet password. See Chapter 4 for more information.
8. A. The command erase-startup-config deletes the configuration stored in NVRAM. See Chapter 4 for more information.
9. C. ICMP is the protocol at the Network layer that is used to send messages back to an originating router. See Chapter 2 for more information.
10. A. Class A addressing provides 24 bits for hosts addressing. See Chapter 3 for more information.
11. C. First, a /22 mask is 255.255.252.0, meaning you have a block size of four in the third octet. The subnet is 172.16.156.0. See Chapter 3 for more information.
12. A. By default, switches break up collision domains but are one large broadcast domain. See Chapter 1 for more information.
13. C. Segmentation happens at the Transport layer. See Chapter 1 for more information.
14. D. Stub networks have only one connection to an internetwork. Only default routes can be set on a stub network or network loops may occur. See Chapter 6 for more information.
15. B. A hub is a Physical layer device. See Chapter 1 for more information.
16. B. The command show controllers s 0 tells you what type of serial connection you have. If it is a DCE, you need to provide the clock rate. See Chapter 4 for more information.
17. C. The primary reason the OSI model was created was so that different networks could interoperate. See Chapter 1 for more information.
18. C. The Transport layer creates virtual circuits between hosts before transmitting any data. See Chapter 1 for more information.
19. C. User Datagram Protocol is a connection network service at the Transport layer, and DHCP uses this connectionless service. See Chapter 2 for more information.
20. D. The command used to copy a configuration from a router to a TFTP host is copy flash tftp. See Chapter 8 for more information.
21. E. The clock rate command is two words, and the speed of the line is in bits per second (bps). See Chapter 5 for more information.
22. C. The command line vty 0 4 places you in a prompt that will allow you to set or change your Telnet password. See Chapter 4 for more information.
23. B. The command enable secret todd sets the enable secret password to todd. See Chapter 4 for more information.
24. C, E. WPA uses PSK to include authentication and can use either static or dynamic encryption keys. The benefit of WPA over a static WEP key is that WPA can change dynamically while the system is used. See Chapter 8 for more information.
25. B. If a device knows the IP address of where it wants to send a packet but doesn't know the hardware address, it will send an ARP broadcast looking for the hardware address or, in this case, the Ethernet address. See Chapter 2 for more information.
26. C. To enable RIP routing on a Cisco router, use the global config command router rip. See Chapter 6 for more information.
27. D. If an AP does have SSID broadcasting disabled, the client needs to set the SSID value of the AP on the client software in order to connect to the AP. See Chapter 8 for more information.
28. A. WPA2 uses the Advanced Encryption Standard (AES) known as the Counter Mode Cipher Block Chaining-Message Authentication Code (CBC-MAC) protocol (CCMP). See Chapter 8 for more information.
29. B, D. Intrusion detection systems (IDSs) and intrusion prevention systems (IPSs). These tools help prevent threats by watching for trends, particular patterns, and other factors. See Chapter 9 for more information.
30. B, C. You should always have a firewall on your network to block access from outside devices. In addition, Cisco recommends always using Secure Shell (SSH) instead of Telnet to configure your devices in-band. See Chapter 9 for more information.