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1. B. LANs generally have a geographic scope of a single building or smaller. They can be simple (two hosts) to complex (with thousands of hosts). See Chapter 1 for more information.

2. B. Star topologies are the easiest to troubleshoot and can easily scale to large sizes. See Chapter 1 for more information.

3. C. IP is a Network layer protocol. Internet Explorer is an example of an Application layer protocol, Ethernet is an example of a Data Link layer protocol, and T1 can be considered a Physical layer protocol. See Chapter 2 for more information.

4. D. Layer 2 of the OSI model is the Data Link layer, which provides the physical transmission of the data and handles error notification, network topology, and flow control. See Chapter 2 for more information.

5. C. Cable modems use RG-6 coax cables. See Chapter 3 for more information.

6. D. To get the high data-transfer speed, like 1Gbps, you need to use a wire standard that is highly rated, such as Category 5e or Category 6. See Chapter 3 for more information.

7. A, B, C. With half duplex, you are using one wire pair with a digital signal either transmitting or receiving (but not both at once). Carrier Sense Multiple Access with Collision Detection (CSMA/CD) helps packets that are transmitted simultaneously from different hosts share bandwidth evenly. See Chapter 4 for more information.

8. B. To connect two switches together or a hub to a switch, you need a crossover cable. See Chapter 4 for more information.

9. A. For the most part, switches are not cheap; however, one of the biggest benefits of using switches instead of hubs in your internetwork is that each switch port is actually its own collision domain. A hub creates one large collision domain. Switches still can't break up broadcast domains (do you know which devices do?). Hubs do not recognize frames and data structures but switches do. See Chapter 5 for more information.

10. C A. switch creates separate collision domains for each port but does not break up broadcast domains by default. See Chapter 5 for more information.

11. D. DNS uses TCP for zone exchanges between servers and UDP when a client is trying to resolve a hostname to an IP address. See Chapter 6 for more information.

12. A. HTTP, FTP, and Telnet use TCP at the Transport layer; however, they are all Application layer protocols, so the Application layer is the best answer for this question. See Chapter 6 for more information.

13. C. Anycast is a new type of communication that replaces broadcasts in IPv4. Anycast addresses identify multiple interfaces, which is the same as multicast; however, the big difference is that the anycast packet is delivered to only one address: the first one it finds defined in terms of routing distance. This address can also be called one-to-one-of-many. See Chapter 7 for more information.

14. B, D. The addresses in the ranges 10.0.0.0 through 10.255.255.255 and 172.16.0.0 through 172.31.255.255 as well as 192.168.0.0 through 192.168.255.255 are all considered private, based on RFC 1918. Use of these addresses on the Internet is prohibited so that they can be used simultaneously in different administrative domains without concern for conflict. See Chapter 7 for more detail on IP addressing and information on private IP addresses.

15. C. This is a pretty simple question. A /28 is 255.255.255.240, which means that our block size is 16 in the fourth octet. 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, and so on. The host is in the subnet 160. See Chapter 8 for more information.

16. B. To test the local stack on your host, ping the loopback interface of 127.0.0.1. See Chapter 8 for more information.

17. C. The Data Link layer is responsible for encapsulating IP packets into frames and for providing logical network addresses. See Chapter 9 for more information.

18. A. Packets specifically have to be carried to a router in order to be routed through a network. See Chapter 9 for more information.

19. A, D. RIP and RIPv2 are distance vector routing protocols. OSPF and IS-IS are link state. See Chapter 10 for more information.

20. D. EIGRP is called a hybrid routing protocol because it uses the characteristics of both distance vector and link state routing protocols. However, EIGRP can only be run on Cisco routers and is not vendor neutral. The new CompTIA objectives mention BGP as a hybrid routing protocol. See Chapter 10 for more information.

21. C. Virtual LANs break up broadcast domains in Layer 2 switched internetworks. See Chapter 11 for more information.

22. C. The Spanning Tree Protocol (STP) was designed to stop Layer 2 loops. All enterprise model switches have STP by default. See Chapter 11 for more information.

23. B. Part of the 802.11n wireless standard, MIMO sends multiple frames by several antennae over several paths; they are then recombined by another set of antennae to optimize throughput and multipath resistance. This is called spatial multiplexing. See Chapter 12 for more information.

24. B, C. At a minimum, you need to change the default SSID value on each AP and configure new usernames and passwords on the AP. See Chapter 12 for more information.

25. A. IPSec works at the Network layer of the OSI model (Layer 3) and secures all applications that operate above it (Layer 4 and above). Additionally, because it was designed by the IETF and designed to work with IPv4 and IPv6, it has broad industry

support and is quickly becoming the standard for VPNs on the Internet. See Chapter 13 for more information.

26. A. RADIUS combines user authentication and authorization into one profile. See Chapter 13 for more information.

27. A. Social engineering, or phishing, refers to the act of attempting to illegally obtain sensitive information by pretending to be a credible source. Phishing usually takes one of two forms: an email or a phone call. See Chapter 14 for more information.

28. A, B, C A. denial of service (DoS) attack prevents users from accessing the system. All of the options are possible denial of service attacks except Virus FloodSyn. See Chapter 14 for more information.

29. D. Changing network configurations, terminating sessions, and deceiving the attacker are all actions that can be taken by an intrusion prevention system (IPS) device. These are all proactive approaches to security. See Chapter 15 for more information.

30. B. Firewalls help provide perimeter network security by allowing or denying connections and types of traffic in or out of the network. See Chapter 15 for more information.

31. A, B, C. Routing Information Protocol (RIP) is not a WAN protocol but a routing protocol used in local area connections. See Chapter 16 for more information.

32. C. The committed information rate (CIR) is the rate, in bits per second, at which the Frame Relay switch agrees to transfer data. See Chapter 16 for more information.

33. A, D. The arp utility's – a and – g switches perform the same function. They both show the current ARP cache. See Chapter 17 for more information.

34. B. To purge and reload the remote NetBIOS name cache, you must use nbtstat –R. Remember that the R must be uppercase, and it will not work correctly without the hyphen before it. See Chapter 17 for more information.

35. B A. wire crimper or crimper is used to attach ends onto different types of network cables. See Chapter 18 for more information.

36. A, B, D. Due to sensitivity to any variation and impedance to cabling, options A, B, and D are all reasons you'd use a TDR. See Chapter 18 for more information.

37. A, B, C. Because most of today's networks still consist of large amounts of copper cable, they can continue to suffer from the physical issues (the options are not a complete list) that have plagued all networks since the very beginning of networking. See Chapter 19 for more information.

38. C. You have just tested your theory of a problem to determine the cause. Based on the standard troubleshooting model, the next step would be to establish a plan of action to resolve the problem and identify potential effects. See Chapter 19 for more information.

39. A. Traffic shaping, also known as packet shaping, is another form of bandwidth optimization. See Chapter 20 for more information.

40. A. Load balancing refers to a technique used to spread work out to multiple computers, network links, or other devices. You can load-balance work on servers by clustering servers so that multiple machines all provide the same service. See Chapter 20 for more information.