ccent ccna icnd1 official exam certification guide - appendixes

CCENT/CCNA ICND1 Official Exam Certification Guide - Appendixes Part VI: Appendixes Appendix A Answers to the “Do I Know This Already?” Quizzes Appendix B Decimal to Binary Conversion Table Appendix C ICND1 Exam Updates: Version 1.0 Glossary 1828xbook.fm Page 575 Thursday, July 26, 2007 3:10 PM 1828xbook.fm Page 576 Thursday, July 26, 2007 3:10 PM A P P E N D I X A Answers to the “Do I Know This Already?” Quizzes Chapter 2 “Do I Know This Already?” 1. D and F 2. A and G 3. B. Adjacent-layer interaction occurs on one computer, with two adjacent layers in the model. The higher layer requests services from the next lower layer, and the lower layer provides the services to the next higher layer. 4. B. Same-layer interaction occurs on multiple computers. The functions defined by that layer typically need to be accomplished by multiple computers—for example, the sender setting a sequence number for a segment, and the receiver acknowledging receipt of that segment. A single layer defines that process, but the implementation of that layer on multiple devices is required to accomplish the function. 5. A. Encapsulation is defined as the process of adding a header in front of data supplied by a higher layer (and possibly adding a trailer as well). 6. D 7. C 8. A 9. F 10. C and E. OSI includes the transport layer (not transmission layer) and the network layer (not Internet layer). 1828xbook.fm Page 577 Thursday, July 26, 2007 3:10 PM 578 Appendix A: Answers to the “Do I Know This Already?” Quizzes Chapter 3 “Do I Know This Already?” 1. D 2. A 3. B 4. B, D, and E. Routers, wireless access point Ethernet ports, and PC NICs all send using pins 1 and 2, whereas hubs and switches send using pins 3 and 6. Straight-through cables are used when connecting devices that use the opposite pairs of pins to transmit data. 5. B 6. A 7. A and C 8. C and D 9. A 10. B, C, and E 11. C Chapter 4 “Do I Know This Already?” 1. B 2. B 3. B 4. A 5. E 6. E. Although HDLC has an Address field, its value is immaterial on a point-to-point link, as there is only one intended recipient, the device on the other end of the circuit. 7. A 8. B. One of the main advantages of Frame Relay is that a router can use a single access link to support multiple VCs, with each VC allowing the router to send data to a different remote router. To identify each VC, the router must use a different DLCI, because the DLCI identifies the VC. 1828xbook.fm Page 578 Thursday, July 26, 2007 3:10 PM Chapter 6 579 Chapter 5 “Do I Know This Already?” 1. A and C. The network layer defines logical addressing, in contrast to physical addressing. The logical address structure allows for easy grouping of addresses, which makes routing more efficient. Path selection refers to the process of choosing the best routes to use in the network. Physical addressing and arbitration typically are data link layer functions, and error recovery typically is a transport layer function. 2. C and E 3. A 4. B. 224.1.1.1 is a class D address. 223.223.223.255 is the network broadcast address for class C network 223.223.223.0, so it cannot be assigned to a host. 5. D 6. D and F. Without any subnetting in use, all addresses in the same network as 10.1.1.1—all addresses in Class A network 10.0.0.0—must be on the same LAN. Addresses separated from that network by some router cannot be in network 10.0.0.0. So, the two correct answers are the only two answers that list a valid unicast IP address that is not in network 10.0.0.0. 7. D 8. F 9. C 10. B and C 11. A and C 12. C 13. D Chapter 6 “Do I Know This Already?” 1. C. TCP uses a concept called forward acknowledgment, in which the acknowledgment field in the header lists the next-expected byte, not the last-received byte. An acknowledgment of 5000 in this case means that the TCP segment with sequence number 5000 was lost, so PC1 should resend that TCP segment. 2. D 3. D and E 1828xbook.fm Page 579 Thursday, July 26, 2007 3:10 PM 580 Appendix A: Answers to the “Do I Know This Already?” Quizzes 4. D and E 5. C. TCP, not UDP, performs windowing, error recovery, and ordered data transfer. Neither performs routing or encryption. 6. C and F. The terms packet and L3PDU refer to the data encapsulated by Layer 3. Frame and L2PDU refer to the data encapsulated by Layer 2. 7. B. Note that the hostname is all the text between the // and the /. The text before the // identifies the application layer protocol, and the text after the / represents the name of the web page. 8. A and D. VoIP flows need better delay, jitter, and loss, with better meaning less delay, jitter, and loss, as compared with all data applications. VoIP typically requires less bandwidth than data applications. 9. C. Intrusion Detection Systems (IDS) monitor packets, comparing the contents of single packets, or multiple packets, to known combinations (signatures) that typically imply that a network attack is occurring. 10. A. A virtual private network (VPN) is a security feature in which two endpoints encrypt data before forwarding it through a public network such as the Internet, providing privacy of the data inside the packets. Chapter 7 “Do I Know This Already?” 1. A. A switch compares the destination address to the MAC address table. If a matching entry is found, the switch knows out which interface to forward the frame. If no matching entry is found, the switch floods the frame. 2. C. A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table). 3. A. A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table). 4. B. Switches learn MAC table entries by noting the source MAC address of each received frame and the interface in which the frame was received, adding an entry that contains both pieces of information (MAC address and interface). 5. A and B. When the frame sent by PC3 arrives at the switch, the switch has learned a MAC address table entry for only 1111.1111.1111, PC1’s MAC address. PC3’s 1828xbook.fm Page 580 Thursday, July 26, 2007 3:10 PM Chapter 9 581 frame, addressed to 2222.2222.2222, is flooded, which means it is forwarded out all interfaces except for the interface on which the frame arrived. 6. A. A collision domain contains all devices whose frames could collide with frames sent by all the other devices in the domain. Bridges, switches, and routers separate or segment a LAN into multiple collision domains, whereas hubs and repeaters do not. 7. A, B, and C. A broadcast domain contains all devices whose sent broadcast frames should be delivered to all the other devices in the domain. Hubs, repeaters, bridges, and switches do not separate or segment a LAN into multiple broadcast domains, whereas routers do. 8. B and D Chapter 8 “Do I Know This Already?” 1. A and B 2. B 3. B 4. A 5. F 6. D 7. B and C Chapter 9 “Do I Know This Already?” 1. B. If both commands are configured, IOS accepts only the password as configured in the enable secret command. 2. B and C 3. B. The first nonblank character after the banner login phrase is interpreted as the beginning delimiter character. In this case, it’s the letter “t.” So, the second letter “t”— the first letter in “the”—is interpreted as the ending delimiter. The resulting login banner is the text between these two “t”s—namely, “his is.” 4. A. The setting for the maximum number of MAC addresses has a default of 1, so the switchport port-security maximum command does not have to be configured. 1828xbook.fm Page 581 Thursday, July 26, 2007 3:10 PM 582 Appendix A: Answers to the “Do I Know This Already?” Quizzes 5. A, D, and F. To allow access via Telnet, the switch must have password security enabled, at a minimum using the password vty line configuration subcommand. Additionally, the switch needs an IP address (configured under the VLAN 1 interface) and a default gateway when the switch needs to communicate with hosts in a different subnet. 6. F 7. E 8. A. VLAN names are case-sensitive, so the name MY-VLAN command, while using the correct syntax, would set a different VLAN name than the name shown in the question. The interface range command in one of the answers includes interfaces Fa0/13, Fa0/14, and Fa0/15. Because Fa0/14 is not assigned to VLAN 2, this command would not have allowed the right VLAN assignment. To assign a port to a VLAN, the switchport access vlan 2 command would have been required (not the switchport vlan 2 command, which is syntactically incorrect). Chapter 10 “Do I Know This Already?” 1. E and F. CDP discovers information about neighbors. show cdp gives you several options that display more or less information, depending on the parameters used. 2. E and F 3. A, B, and D. The disabled state in the show interfaces status command is the same as an “administratively down and down” state shown in the show interfaces command. The interface must be in a connect state (per the show interfaces status command) before the switch can send frames out the interface. 4. A and D. SW2 has effectively disabled IEEE standard autonegotiation by configuring both speed and duplex. However, Cisco switches can detect the speed used by the other device, even with autonegotiation turned off. Also, at 1 Gbps, the IEEE autonegotiation standard says to use full duplex if the duplex setting cannot be negotiated, so both ends use 1 Gbps, full duplex. 5. B and D. The show interfaces command lists the actual speed and duplex setting, but it does not imply anything about how the settings were configured or negotiated. The show interfaces status command lists a prefix of a- in front of the speed and duplex setting to imply that the setting was autonegotiated, leaving off this prefix if the setting was configured. 6. A, B, and D. For Fa0/1, autonegotiation should work normally, with both switches choosing the faster speed (100) and better duplex setting (full). Autonegotiation also works on SW1’s Fa0/2, with both switches choosing the 100 Mbps and FDX setting. 1828xbook.fm Page 582 Thursday, July 26, 2007 3:10 PM Chapter 11 583 Fa0/3 disables autonegotiation as a result of having both the speed and duplex configured. The other switch still automatically senses the speed (100 Mbps), but the autonegotiation failure results in the other switch using half duplex. 7. A and C. Switch forwarding logic and MAC table entries are separated per VLAN. Because the frame came in an interface in VLAN 2, it will only be forwarded based on VLAN 2’s MAC table entries, and it will only cause the addition of MAC table entries in VLAN 2. The output from the show mac address-table dynamic command lists only dynamic MAC table entries, so you cannot definitively state how the frame will be forwarded, because the static entries are not listed. 8. B and C. IOS adds MAC addresses configured by the port security feature as static MAC addresses, so they do not show up in the output of the show mac address-table dynamic command. show mac address-table port-security is not a valid command. Chapter 11 “Do I Know This Already?” 1. A. 802.11b uses only the ISM band (around 2.4 GHz), and 802.11g can use both ISM and U-NII. 802.11i is a security standard. 2. B. 802.11a uses only OFDM, and 802.11b uses only DSSS. 802.11g runs at a maximum of 54 Mbps using OFDM encoding. 3. C 4. A. The Extended Service Set (ESS) mode uses multiple access points, which then allows roaming between the APs. BSS uses a single AP, and IBSS (ad hoc mode) does not use an AP, so roaming between different APs cannot be done with BSS and IBSS. 5. A and C. APs need to know the SSID for the WLAN the AP is supporting and, if an AP is capable of multiple standards, the wireless standard to use. The AP uses the best speed to each device based on the signal quality between the AP and that device; the speed can vary from device to device. The size of the coverage area is not configured; instead, it is impacted by antenna choice, antenna gain, interference, and the wireless standard used. 6. B. The AP connects to a LAN switch using a straight-through cable, just like an end-user device. All APs in the same ESS should connect to the same VLAN, because all clients connected to the same WLAN should be in the same subnet. Like LAN switches, APs do not need IP configuration to forward traffic, although it is useful for managing and accessing the AP. The standard or speed used on the WLAN does not require any particular Ethernet speed on the wired side of the AP, although overall performance is better when using faster WLAN speeds by using at least 100-Mbps Ethernet. 1828xbook.fm Page 583 Thursday, July 26, 2007 3:10 PM [...]... following: 1 Mentions technical items that might not have been mentioned elsewhere in the book 2 Covers new topics when Cisco adds topics to the ICND1 or CCNA exam blueprints 3 Provides a way to get up-to-the-minute current information about content for the exam Always Get the Latest at the Companion Website You are reading the version of this appendix that was available when your book was printed However,... 2007 3:10 PM GLOSSARY 10BASE-T The 10-Mbps baseband Ethernet specification using two pairs of twisted-pair cabling (Categories 3, 4, or 5): One pair transmits data and the other receives data 10BASE-T, which is part of the IEEE 802.3 specification, has a distance limit of approximately 100 m (328 feet) per segment 100BASE-TX A name for the IEEE Fast Ethernet standard that uses two-pair copper cabling, a... APPENDIX C ICND1 Exam Updates: Version 1.0 Over time, reader feedback allows Cisco Press to gauge which topics give our readers the most problems when taking the exams Additionally, Cisco may make small changes in the breadth of exam topics or in emphasis of certain topics To assist readers with those topics, the author creates new materials clarifying and expanding upon those troublesome exam topics... packets going left-to-right, with those addresses reversed for the ping reply packets that go right-to-left The MAC addresses always represent the addresses of the devices on that local LAN Note that HDLC, on the serial link, does not use MAC addresses Chapter 16 “Do I Know This Already?” 1 D Modems demodulate an analog signal sent by the phone company into a digital signal The goal is to re-create the original... encapsulation command resets the encapsulation (data-link), so only the encapsulation ppp command is required The clock rate command only matters if a back-to-back serial link is used, and if that link already works, that means the clock rate command has already been configured The bandwidth command is never required to make the link work 2 B For a back-to-back serial link, the clock rate command is required... of one-digit binary numbers The result is another one-digit binary number 1 AND 1 yields 1; all other combinations yield a 0 boot field The low-order 4 bits of the configuration register in a Cisco router The value in the boot field in part tells the router where to look for a Cisco IOS image to load BRI Basic Rate Interface An ISDN interface composed of two 64-kbps bearer (B) channels and one 16-kbps... are received, in which case, in a well-designed LAN, collision fragments should not occur as a result of this forwarding logic frame A term referring to a data-link header and trailer, plus the data encapsulated between the header and trailer Frame Relay An international standard data-link protocol that defines the capabilities to create a frame-switched (packet-switched) service, allowing DTE devices... (running-config) 603 1828xbook.fm Page 604 Thursday, July 26, 2007 3:10 PM 604 configuration register configuration register In Cisco routers, a 16-bit, user-configurable value that determines how the router functions during initialization In software, the bit position is set by specifying a hexadecimal value using configuration commands connection establishment The process by which a connection-oriented... typically a CSU/DSU, is the DCE From a packet-switching perspective, the service provider’s switch, to which a router might connect, is considered the DCE decapsulation On a computer that receives data over a network, the process in which the device interprets the lower-layer headers and, when finished with each header, removes the header, revealing the next-higher-layer PDU default gateway/default router... subnet has the same numeric value as the classful network’s network-wide broadcast address bus A common physical signal path composed of wires or other media across which signals can be sent from one part of a computer to another C CDP Cisco Discovery Protocol A media- and protocol-independent devicediscovery protocol that runs on most Cisco-manufactured equipment, including routers, access servers, and . CCENT/ CCNA ICND1 Official Exam Certification Guide - Appendixes Part VI: Appendixes Appendix A Answers to the “Do I Know This Already?”. destination of 172.16.2.7 for the packets going left-to-right, with those addresses reversed for the ping reply packets that go right-to-left. The MAC addresses always represent the addresses. addresses, so they do not show up in the output of the show mac address-table dynamic command. show mac address-table port-security is not a valid command. Chapter 11 “Do I Know This Already?” 1.