Chapter 18 1039 Chapter 18 1. When a technician performs basic testing of a network, which of the following is true? A. The technician should proceed in sequence from one OSI reference model layer to the next. 2. What approach should a technician start with when he/she troubleshoots a network? A. The technician should start with a structured approach. 3. When a technician troubleshoots a problem on a network, which layer of the OSI model should he/she begin with? A. Begin with Layer 1 4. If a technician wants to test network connectivity, which basic command should be used? B. ping 5. When a network administrator wants to verify the application layer software between source and destination stations, which of the following commands should be used? B. telnet 6. You suspect that one of the routers connected to your network is sending bad routing information. What command can you use to check? B. router# show ip route 7. Why would you display the IP routing table? D. To set the parameters and filters for the router 8. If you wanted to see RIP routing updates as they are sent and received, what command structure would you use? C. router# debug ip rip 9. The dynamic output of the debug command comes at a performance cost, which produces processor overhead? A. High 10. By default, the router sends the debug output and system messages to what? A. The console 1102.book Page 1039 Tuesday, May 20, 2003 2:53 PM 1040 Appendix C: Check Your Understanding Answer Key 11. The telnet command provides what type of terminal? B. Virtual 12. ICMP stands for what? C. Internet Control Message Protocol 13. Most interfaces or NICs have what type of lights that show whether there is a valid connection? A. Indicator 14. Telnet is used at what layer of the OSI reference model? D. Layer 7 15. If the routing protocol is not enabled or the IP address cannot be determined, at which layer of the OSI model should an administrator begin to look? C. Layer 3 Chapter 19 1. Which of the following best describes TCP/IP? A. It is a suite of protocols that can be used to communicate across any set of interconnected networks. 2. Which of the following is one of the protocols found at the transport layer? B. UDP 3. What is the purpose of port numbers? A. They keep track of different conversations crossing the network at the same time. 4. Which of the following best describes UDP? D. A protocol that exchanges datagrams without acknowledgments or guaran- teed delivery 5. Which of the following TCP/IP layers includes file transfer, e-mail, remote login, and network management? B. Application 6. Why are TCP three-way handshake/open connections used? A. To ensure that lost data can be recovered if problems occur later 1102.book Page 1040 Tuesday, May 20, 2003 2:53 PM Chapter 20 1041 7. What does a TCP sliding window do? C. It allows the window size to be negotiated dynamically during the TCP session, which results in more efficient use of bandwidth. 8. UDP segments use what protocols to provide reliability? B. Application layer protocols 9. Which of the following best describes window size? B. The number of messages or bytes that can be transmitted while awaiting an acknowledgment 10. What is the function of ARP? C. It is used to map an IP address to a MAC address. Chapter 20 1. Common ACL functions include filtering packets internally, protecting the inter- nal network from illegal Internet access, and restricting access to virtual terminal ports. True or false? A. True 2. ACL is an acronym for: D. Access control list 3. A(n) ACL works by comparing the source IP address against the ACL rules. C. Standard 4. A(n) ACL works by comparing the source IP address, destination IP address, or other parameters against the ACL rules. A. Extended 5. A(n) ACL uses names instead of numbers to distinguish ACLs. B. Named 6. As a general rule, ACLs should be placed where in the network? C. Closest to the traffic to be controlled 1102.book Page 1041 Tuesday, May 20, 2003 2:53 PM 1042 Appendix C: Check Your Understanding Answer Key 7. In a firewall architecture, which router most likely will be configured with an ACL? C. The exterior router 8. Named ACLs were introduced in Cisco IOS 11.2. True or false? B. False 9. What command is used to apply an ACL to a VTY port? A. ip access-list 10. Which of the following commands would you use to find out whether any ACLs are set on an interface? C. show ip interface 11. What do you call the additional 32 bits of information in the access-list statement? A. Wildcard bits 12. If you want to permit traffic based on its addressing or protocol type, you would use which of the following commands? B. Router (config)#access-list access-list number {permit | deny} {test conditions} 13. Standard IP access lists permit or deny routing of a packet based on the IP address that it originates from and the protocol suite that it is destined for. True or false? A. True 14. Access lists impact network security based on which of the following factors? C. The source subnet/host/network of the packets 15. What type of networking device would be needed to implement access lists to increase network security? B. Router 16. What does the following access list allow? access-list 1 permit 204.211.19.162 0.0.0.0 B. “Permit a specific host.” 1102.book Page 1042 Tuesday, May 20, 2003 2:53 PM Chapter 20 1043 Answers to Hints in Appendix A What is the purpose of this floor? Answer: Warehouse, reception area What door will workers move freight through? Answer: The large garage doors at the rear of the building What doors will visitors come in? Answer: Front doors off lobby that has reception station in it. Where are visitors most likely to go after they sign in? Answer: The conference room adjacent to the reception area Where would you consider using wireless technology? Answer: Guests could log on to the Internet via wireless in the reception and conference areas. Warehouse staff could use wireless for inventory. If your department someday is tasked with wiring IP security cameras, what areas would you want to keep under surveillance? Answer: The two secure storage areas, the rear walkthrough door, and the reception area From where does the telephone company serve this building? Answer: There is a point of presence [POP] next to the mechanical room. What kind of lock should it have? Answer: A good one that can be opened from the inside Would the POP be a good place for the servers? Answer: Possibly—it is certainly big enough and is close to the elevators, for easy access. If it is determined that the server room must exist separate from the POP, what consid- erations should guide its location? Answer: The location should be in a TR and should be on a middle floor. Could you install the risers in the POP? Answer: No. Check the floor above, and you will see that it has a conference room in that position. Where might you install the risers? Answer: There is a small hallway adjacent to each stairway. Check that out. 1102.book Page 1043 Tuesday, May 20, 2003 2:53 PM 1044 Appendix C: Check Your Understanding Answer Key The horizontal cabling always should go parallel to walls. Getting to Room 1.2 while staying parallel to walls makes a cable run of how many meters? Is this useable? Answer: The distance is about 94 meters. This is barely enough to make the run, go down the walls, and join a work-area connector. The designer must decide whether to cheat a little bit or to take advantage of the wireless system that is installed for the warehouse or conference room. This would present a security hassle but would solve a major problem. Where might you put the telecommunications room on Floor 2? You might consider using two of them. Answer: Room 2.31 because it offers ceiling access to Room 3.10 above and to the mechanical room below. You might need to add one at Room 2.7 to accommodate the offices against that wall. Floor 3 has large unplanned spaces in Rooms 3.1 and 3.2. If you place the telecommu- nications room in Room 3.10, how can you serve these spaces, especially the far side of Room 3.2? Answer: Wireless is a good solution for now. Then when the rooms are built out, put a second telecommunications room in either of them. You notice a large deck on Floor 4, as well as a banquet area with a piano. What would you need to provide network connectivity to this area? Answer: You would need only one TR and some wireless to serve this area. Where will you put the TR? Answer: This is tough. Room 4.5 seems to be an office. However, Room 4.8 is blank. Also, there is a hallway with an exterior door shown next to the staircase by Room 4.10. Because this is the fourth floor, you suspect an error. Furthermore, Room 4.10 is shown with a door facing into a stairwell. Chances are, you could mention these apparent errors and at the same time request that a TR be installed between Rooms 4.4 and 4.5. 1102.book Page 1044 Tuesday, May 20, 2003 2:53 PM 1102.book Page 1045 Tuesday, May 20, 2003 2:53 PM 1102.book Page 1046 Tuesday, May 20, 2003 2:53 PM Index Numerics 4B/5B encoding, 329 5-4-3 rule, 216, 320 8B1Q4 encoding, 339 10BASE2, 321–322 10BASE5, 320–321 10BASE-T, 322–323, 325 architecture, 326–328 link pulse, 323 10-Gbps Ethernet, 347–350 architecture, 350, 352–353 10-Mbps Ethernet, 317 5-4-3 rule, 320 line encoding, 318 Manchester encoding, 318 100BASE-FX, 328, 332–334 100BASE-T, 329, 331–332 100BASE-TX, 328 110-blocks, 938 802.1X/EAP, 224–225 1000BASE-LX, 342–344 1000BASE-SX, 342–345 1000BASE-T, 339–342 1000-Mbps Ethernet, 337–339 A AAA servers, 90 absorption, 150 AC voltage, 119 access methods, CSMA/CD, 268, 271 backoff algorithm, 276 access VPNs, 56 accessing CLI on Cisco IOS routers, 566–569 global configuration mode, 593 acknowledgments, 485 PAR, 826–827 ACLs, 841–842 configuring, 847 extended, 855–861 defaults, 862–863 ICMP configuration, 861–862 functions of, 843 bit buckets, 845 named, 863–867 on firewall routers, 868 restricting vty access, 869–870 standard, 852–854 verifying, 870–871 active hubs, 218 ad hoc networks, 162 ADA (Americans with Disabilities Act), 901 adapter cards, NICs, 12–13 modem installation, 13–14 Address field (Ethernet frames), 261 address mask requests, 777–778 administrative distance, 683–684, 724 alien crosstalk, 196 alignment errors, 284–285 all band interference, 169 Alohanet, 252 always-on services, 15 amplitude, 184 analog bandwidth, 66, 190 1102.book Page 1047 Tuesday, May 20, 2003 2:53 PM 1048 analyzing debug ip packet detail command output, 807–808 debug ip rip command output, 806–807 AND operator, 31 ANDing, 463, 465 angle of incidence, 137 angle of reflection, 137 any wildcard, 850–851 application layer (OSI model), 71, 491 connection establishment/termination, 493–494 direct network applications, 492 DNS, 494–495 FTP, 495–496 HTTP, 496–497 indirect network support, 492–493 SMTP, 497–498 SNMP, 498 TCP/IP model, 377–378 Telnet, 499–500 troubleshooting, 797–798 applications, 18 applying descriptions to interfaces, 604–605 passwords to Telnet sessions, 596 APs (access points), 164 wireless, 92 architecture of 10-Gbps Ethernet, 350–353 of Fast Ethernet, 334–337 of Gigabit Ethernet, 345–347 of Internet, 383–385 scalability, 385 of TBASE-T, 326–328 ARP (Address Resolution Protocol), 408, 834 default gateways, 411 operation within subnets, 410 ASCII (American Standard Code for Information Interchange), 19 assigned port numbers for services, 831–832 assignment of IP addresses, 407 BOOTP assignment, 414–415 DHCP assignment, 415–417 RARP assignment, 412–414 static assignment, 408 ATM (Asynchronous Transfer Mode), cell switching, 523 atoms, 115 Bohr model, 116 electrons, 117 attacks, preventing DoS attacks during synchronization, 823 attenuation, 195–196 AUI connectors, 210 authentication on WLANs, 166–168 autonegotiation, 285 FLP bursts, 287 autonomous systems, 443, 539, 692 availability quantifying, 514 uptime, 513 B backbone cabling, 893–894 fiber-optic, 894–896 backbone tree topology, 98 backing up configuration files, 608 backoff algorithms, 269, 276 backplane, 10 balanced hybrid routing protocols, 692, 701 bandwidth, 58, 233, 442 analog, 190 characteristics of, 58 data transfer calculations, 64–66 digital, 191 versus analog, 66 highway analogy, 59 limitations of, 61–63 measurements of, 61 pipe analogy, 59 throughput, 64 bandwidth domains, 81 analyzing 1102.book Page 1048 Tuesday, May 20, 2003 2:53 PM . encoding, 329 5-4-3 rule, 21 6 , 320 8B1Q4 encoding, 339 10 BASE2, 3 21 322 10 BASE5, 320 –3 21 10BASE-T, 322 – 323 , 325 architecture, 326 – 328 link pulse, 323 10 -Gbps Ethernet, 347–350 architecture, 350, 3 52 353 10 -Mbps. 3 52 353 10 -Mbps Ethernet, 317 5-4-3 rule, 320 line encoding, 318 Manchester encoding, 318 10 0BASE-FX, 328 , 3 32 334 10 0BASE-T, 329 , 3 31 3 32 10 0BASE-TX, 328 11 0-blocks, 938 8 02. 1X/EAP, 22 4 22 5 10 00BASE-LX,. installed between Rooms 4.4 and 4.5. 11 02. book Page 10 44 Tuesday, May 20 , 20 03 2: 53 PM 11 02. book Page 10 45 Tuesday, May 20 , 20 03 2: 53 PM 11 02. book Page 10 46 Tuesday, May 20 , 20 03 2: 53 PM Index Numerics 4B/5B