1. C. 2100 boots the router into ROM monitor mode, 2101 loads the mini-IOS from ROM, and 2102 is the default and loads the IOS from flash. See Chapter 7 for more information.

      2. D. The show license udi command displays the unique device identifier (UDI) of the router, which comprises the product ID (PID) and serial number of the router. See Chapter 7 for more information.

      3. B. The show license feature command allows you to view the technology package licenses and feature licenses that are supported on your router along with several status variables related to software activation and licensing, both licensed and unlicensed features. See Chapter 7 for more information.

      4. B. There are eight different trap levels. If you choose, for example, level 3, level 0 through level 3 messages will be displayed. To specify level 3 the command is logging trap errors. See Chapter 7 for more information.

      5. B. This can be a hard question if you don't remember to invert the 7th bit of the first octet in the MAC address! Always look for the 7th bit when studying for the Cisco R/S, and when using EUI-64, invert it. The EUI-64 autoconfiguration inserts an FF: FE in the middle of the 48-bit MAC address to create a unique IPv6 address. See Chapter 1 for more information.

      6. A. The NDP neighbor advertisement (NA) contains the MAC address. A neighbor solicitation (NS) was initially sent asking for the MAC address. See Chapter 1 for more information.

      7. B. Each field in an IPv6 address is 16 bits long. An IPv6 address has eight fields for a total of 128 bits. See Chapter 1 for more information.

      8. C. The command line console 0 places you at a prompt where you can then set your console user-mode password. See Chapter 6 for more information.

      9. B, D. The mask 255.255.254.0 (/23) used with a Class A address means that there are 15 subnet bits and 9 host bits. The block size in the third octet is 2 (256 – 254). So this makes the subnets in the interesting octet 0, 2, 4, 6, etc., all the way to 254. The host 10.16.3.65 is in the 2.0 subnet. The next subnet is 4.0, so the broadcast address for the 2.0 subnet is 3.255. The valid host addresses are 2.1 through 3.254. See Chapter 1 for more information.

      10. C. The IP address is configured under a logical interface, called a management domain or VLAN 1, by default. See Chapter 2 for more information.

      11. A. 256 – 192 = 64, so 64 is our block size. Just count in increments of 64 to find our subnet: 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 1 for more information.

      12. C. An inside global address is considered to be the IP address of the host on the private network after translation. See Chapter 5 for more information.

      13. B. Once you create your pool, the command ip nat inside source must be used to say which inside locals are allowed to use the pool. In this question, we need to see if access list 100 is configured correctly, if at all, so show access-list is the best answer. See Chapter 6 for more information.

      14. D. Layer 2 switching creates individual collision domains per port. See Chapter 2 for more information.

      15. 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 6 for more information.

      16. B. To see the contents of all access lists, use the show access-list command. See Chapter 6 for more information.

      17. C. VLANs break up broadcast domains at layer 2. See Chapter 2 for more information.

      18. A. The command erase startup-config deletes the configuration stored in NVRAM. Using erase-startup will also work as the IOS will complete the command for you. See Chapter 7 for more information.

      19. C. ICMP is the protocol at the Network layer that is used to send messages back to an originating router. See Chapter 1 for more information.

      20. A. Class A addressing provides 22 bits for host subnetting. Class B provides 16 bits, but only 14 are available for subnetting. Class C provides only 6 bits for subnetting. See Chapter 1 for more information.

      21. B. Only the EIGRP route will be placed in the routing table because EIGRP has the lowest administrative distance (AD), and that is always used before metrics. See Chapter 3 for more information.

      22. D. Switches send information about only one VLAN down a link unless it is configured as a trunk link. See Chapter 2 for more information.

      23. A. By default, switches break up collision domains on a per-port basis but are one large broadcast domain. See Chapter 2 for more information.

      24. C, D. VLAN Trunking Protocol (VTP) is not right because it has nothing to do with trunking except that it sends VLAN information across a trunk link. 802.1q and ISL encapsulations are used to configure trunking on a port. See Chapter 2 for more information.

      25. D. Stub networks have only one connection to an internetwork. Default routes should be set on a stub network or network loops may occur; however, there are exceptions to this rule. See Chapter 3 for more information.

      26. B. Hubs regenerate electrical signals, which are specified at the Physical layer. See Chapter 1 for more information.

      27. A, C. Standard and extended access control lists (ACLs) are used to configure security on a router. See Chapter 6 for more information.

      28. C. If you start at 192.168.128.0 and go through 192.168.159.0, you can see that this is a block of 32 in the third octet. Since the network address is always the first one in the range, the summary address is 192.168.128.0. What mask provides a block of 32 in the third octet? The answer is 255.255.224.0, or /19. See Chapter 1 for more information.

      29. B. The command to back up the configuration on a router is copy running-config startup-config. See Chapter 7 for more information.

      30. C. IEEE 802.3ab is the standard for 1 Gbps on twisted-pair. See Chapter 1 for more information.