Summary
This chapter discussed many of the tools and technologies used in the local area network to address problems typically faced by network designers. Newer technologies, such as ATM LANE, were covered, in addition to more traditional tools and technologies, including Ethernet routers and switches.
Specific attention was given to:
- • LAN technologies
- • Ethernet
- • Token Ring
- • FDDI
- • ATM
- • ATM LANE
- • Interconnectivity tools
- • Repeaters
- • Hubs
- • Switches
- • Routers
- • Problem categories
- • Media
- • Transport
- • Protocols
- • Trunking protocols
- • ISL
- • 802.1q
- • 802.10
- • LANE
The chapter defined key components in network design, including the interconnectivity tools in frame-based networks. It also presented the ATM components: LECS, LEC, LES, and BUS. Finally, it reviewed building topologies, including distributed and collapsed backbones.
Much of the text in the following chapters will focus more on Layers 2 and 3 of the OSI model, so readers will become comfortable with the various functions of hardware in the network and the limitations.
Review Questions
- 1. Broadcasts are controlled by which of the following devices?
- A. Bridges
- B. Repeaters
- C. Routers
- D. Switches
- 2. Routers perform which of the following functions?
- A. Access control
- B. Logical structure
- C. Media conversions
- D. None of the above
- 3. Which of the following devices operate at Layer 2 of the OSI model?
- A. Routers
- B. Gateways
- C. Switches
- D. Bridges
- 4. Which of the following is true regarding cut-through switching?
- A. The frame is forwarded following verification of the CRC.
- B. The frame is forwarded following verification of the HEC.
- C. The frame is forwarded upon receipt of the header destination address.
- D. The frame is forwarded out every port on the switch.
- 5. Which of the following is true regarding store-and-forward switching?
- A. The frame is forwarded following verification of the CRC.
- B. The frame is forwarded following verification of the HEC.
- C. The frame is forwarded upon receipt of the header destination address.
- D. The frame is forwarded out every port on the switch.
- 6. Negating overhead and conversions, the designer chooses to replace the legacy FDDI ring with an ATM switch attached via OC-3. Assuming a backbone of 10 devices, no overhead, and equal distributions, the increase in available bandwidth per device is:
- A. 55Mbps
- B. 100Mbps
- C. 145Mbps
- D. 1Gbps
- E. 1.54Gbps
- 7. An Ethernet switch:
- A. Defines the collision domain
- B. Defines the broadcast domain
- C. Defines both the broadcast and collision domains
- D. Sends all broadcasts to the BUS (broadcast and unknown server)
- 8. Which of the following would be a reason to not span a VLAN across the WAN?
- A. VLANs define broadcast domains, and all VLAN broadcasts would have to traverse the WAN, which typically uses slow links.
- B. Reduced costs, since fewer router interfaces are required.
- C. Easier addressing during moves.
- D. Non-routed workgroup traffic across geographically removed locations.
- 9. Which of the following are considered WAN design issues?
- A. Bandwidth
- B. Cost
- C. Service availability
- D. Protocol support
- E. Remote access
- F. All of the above
- 10. The Cisco IOS offers some benefits to designers regarding WAN deployments. These benefits do not include which of the following?
- A. Compression
- B. Filters
- C. HTTP proxy
- D. On-demand bandwidth
- E. Efficient routing protocols, including EIGRP, NLSP, and static routes
- 11. Which of the following reasons might influence a designer to use a single WAN protocol?
- A. Easier configuration
- B. More-difficult configuration
- C. More-difficult troubleshooting
- D. Increased traffic
- 12. Which of the following is not an open standard?
- A. 802.10
- B. 802.3
- C. 802.1q
- D. ISL
- 13. Which of the following would be valid technical reasons to readdress the IP network?
- A. Implementation of VLSM
- B. Implementation of HSRP
- C. Implementation of EIGRP
- D. Implementation of OSPF
- 14. A distributed backbone typically:
- A. Contains a single router in the data center
- B. Is completely flat within the building or campus
- C. Contains multiple routers, typically with one per floor or area
- D. Requires the use of ATM LANE, version 2.0
- 15. ATM uses:
- A. 53-byte cells
- B. 53-byte frames
- C. Variable-length cells
- D. Variable-length frames
- 16. Which of the following is optional in ATM LANE?
- A. LEC
- B. LES
- C. BUS
- D. LECS
- 17. Which function is used to convert frames to cells?
- A. LES
- B. LEC
- C. LECS
- D. SAR
- 18. Excessive broadcasts are typically resolved with (select three):
- A. Switches
- B. Tuning of the network protocol
- C. Replacement of the network protocol
- D. Routers
- 19. Transport issues differ from media issues in that:
- A. Media issues relate to Layer 1, while transport issues relate to Layer 3.
- B. Media issues involve voice and video, while transport issues are related to increased demand by existing services.
- C. Transport issues incorporate voice and video services, while media issues are limited to the offered load on the network.
- D. None of the above.
- 20. Addressing issues are the responsibility of:
- A. Hubs
- B. Servers
- C. Switches
- D. Routers
Answers to Review Questions
- 1. C.
- 2. A, B, C.
- 3. C, D.
- 4. C.
- 5. A.
- 6. C.
FDDI operates at 100Mbps. With 10 shared stations, each station receives 10Mbps. OC-3 switched offers 155Mbps per station.
- 7. A.
- 8. A.
- 9. F.
- 10. C.
- 11. A.
- 12. D.
- 13. A.
While not covered until Chapter 4, readdressing for OSPF and EIGRP is common, making C and D correct as well.
- 14. C.
- 15. A.
- 16. D.
- 17. D.
- 18. B, C, D.
Routers are a poor choice for resolving excessive broadcasts, although they can divide the broadcast domain. Switches may offer broadcast suppression, but this feature is more appropriate for broadcast storms than for normal broadcast traffic.
- 19. C.
- 20. D.