CCDA FAQ: Network Structure Models

CCDA FAQ: Network Structure Models

Q1. In the hierarchical network model, which layer is responsible for fast transport?
a. Network
b. Core
c. Distribution
d. Access

Answer: B. The core layer of the hierarchical model is responsible for fast transport.

Q2. Which Enterprise Architecture model component interfaces with the service provider (SP)?
a. Campus infrastructure
b. Access layer
c. Enterprise edge
d. Edge distribution

Answer: C. The enterprise edge consists of e-commerce, Internet connectivity, VPN/remote access, and WAN modules. The enterprise edge modules connect to SPs.

Q3. In the hierarchical network model, at which layer do security filtering, address aggregation, and media translation occur?
a. Network
b. Core
c. Distribution
d. Access

Answer: C. The distribution layer of the hierarchical model is responsible for security filtering, address and area aggregation, and media translation.

Q4. Which of the following is/are method(s) of workstation-to-router redundancy in the access layer?
a. AppleTalk Address Resolution Protocol (AARP)
b. Hot Standby Router Protocol (HSRP)
c. Virtual Router Redundancy Protocol (VRRP)
d. Answers B and C
e. Answers A, B, and C

Answer: D. HSRP and VRRP provide default gateway redundancy.

Q5. The network-management module has tie-ins to which component(s)?
a. Campus infrastructure
b. Server farm
c. Enterprise edge
d. SP edge
e. Answers a and b
f. Answers a, b, and c
g. Answers a, b, c, and d

Answer: F. The network management module monitors all components and functions except the SP edge.

Q6. Which of the following is an SP edge module in the Cisco Enterprise Architecture model?
a. Public switched telephone network (PSTN) service
b. Edge distribution
c. Server farm
d. Core layer

Answer: A. The SP edge includes Internet, PSTN, and WAN modules.

Q7. In which module would you place Cisco Unified Communications Manager (CUCM)?
a. Campus core
b. E-commerce
c. Server farm
d. Edge distribution farm

Answer: C. The server farm hosts campus servers including Cisco CallManager servers.

Q8. High availability, port security, and rate limiting are functions of which hierarchical layer?
a. Network
b. Core
c. Distribution
d. Access

Answer: D. The access layer functions are high availability, port security, rate limiting, ARP inspection, virtual access lists, and trust classification.

Q9. True or false: The core layer of the hierarchical model does security filtering and media translation.

Answer: False

Q10. True or false: The access layer provides high availability and port security.

Answer: True

Q11. You add Communications Manager to the network as part of a Voice over IP (VoIP) solution. In which submodule of the Enterprise Architecture model should you place Communications Manager?

Answer: The server farm.

Q12. True or false: HSRP provides router redundancy.

Answer: True

Q13. Which enterprise edge submodule connects to an ISP?

Answer: The Internet submodule.

Q14. List the six modules of the Cisco Enterprise Architecture model for network design.

Answer: Enterprise campus, enterprise edge, enterprise WAN, enterprise branch, enterprise data center, and enterprise teleworker.

Q15. True or false: In the Cisco Enterprise Architecture model, the network management submodule does not manage the SP edge.

Answer: True

Q16. True or false: You can implement a full-mesh network to increase redundancy and reduce a WAN’s costs.

Answer: False. A full-mesh network increases costs.

Q17. How many links are required for a full mesh of six sites?

Answer: Use n(n – 1)/2, where n = 6. 6 * (6 – 1)/2 = (6 * 5)/2 = 30/2 = 15

Q18. List and describe four options for multihoming to the SP between the Enterprise Edge and the SP Edge. Which option provides the most redundancy?


  • Option 1: Single router, dual links to one ISP
  • Option 2: Single router, dual links to two ISPs
  • Option 3: Dual routers, dual links to one ISP
  • Option 4: Dual routers, dual links to two ISPs

Option 4 provides the most redundancy, with dual local routers, dual links, and dual ISPs.

Q19. To what enterprise edge submodule does the SP Edge Internet submodule connect?

Answer: The SP edge Internet submodule connects to the enterprise edge Internet submodule.

Q20. What are four benefits of hierarchical network design?

Answer: Cost savings, ease of understanding, easy network growth (scalability), and improved fault isolation.

Q21. In an IP telephony network, in which submodule or layer are the IP phones and CUCM servers located?

Answer: IP phones reside in the building access layer of the campus infrastructure. The CallManagers are placed in the server farm of the enterprise campus.

Q22. Match the redundant model with its description:
i. Workstation-router redundancy
ii. Server redundancy
iii. Route redundancy
iv. Media redundancy
a. Cheap when implemented in the LAN and critical for the WAN
b. Provides load balancing
c. Host has multiple gateways
d. Data is replicated

Answer: i = C, ii = D, iii = B, iv = A

Q23. True or false: Small to medium campus networks must always implement three layers of hierarchical design.

Answer: False. Small campus networks can have collapsed core and distribution layers and implement a two-layer design. Medium campus networks can have two-tier or three tier designs.

Q24. How many full-mesh links do you need for a network with ten routers?

Answer: Use the formula n(n – 1)/2, where n = 10. 10(10 – 1)/2 = 90/2 = 45 links.

Q25. Which layer provides routing between VLANs and security filtering?
a. Access layer
b. Distribution layer
c. Enterprise edge
d. WAN module

Answer: B. The distribution layer provides routing between VLANs and security filtering.

Q26. List the four modules of the enterprise edge area.

Answer: E-commerce, Internet, VPN/remote access, and WAN.

Q27. List the three submodules of the SP edge.

Answer: Internet services, WAN services, and PSTN services.

Q28. List the components of the Internet edge.

Answer: Firewalls, Internet routers, FTP/HTTP servers, SMTP mail servers, and DNS servers.

Q29. Which submodule contains firewalls, VPN concentrators, and ASAs?
a. WAN
b. VPN/remote access
c. Internet
d. Server farm

Answer: B. The VPN/remote access submodule contains firewalls, VPN concentrators, and ASAs.

Q30. Which of the following describe the access layer? (Select two.)
a. High-speed data transport
b. Applies network policies
c. Performs network aggregation
d. Concentrates user access
e. Provides PoE
f. Avoids data manipulation

Answer: D and E. The access layer concentrates user access and provides PoE to IP phones.

Q31. Which of the following describe the distribution layer? (Select two.)
a. High-speed data transport
b. Applies network policies
c. Performs network aggregation
d. Concentrates user access
e. Provides PoE
f. Avoids data manipulation

Answer: B and C. The distribution layer concentrates the network access switches and routers and applies network policies with access lists.

Q32. Which of the following describe the core layer? (Select two.)
a. High-speed data transport
b. Applies network policies
c. Performs network aggregation
d. Concentrates user access
e. Provides PoE
f. Avoids data manipulation

Answer: A and F. The core layer provides high-speed data transport without manipulating the data.

Q33. Which campus submodule connects to the enterprise edge module?
a. SP edge
b. WAN submodule
c. Building distribution
d. Campus core
e. Enterprise branch
f. Enterprise data center

Answer: D. The Campus Core connects to the server farm, the Enterprise Edge, and the Building Distribution.

Q34. Which remote module connects to the enterprise via the Internet or WAN submodules and contains a small LAN switch for users?
a. SP edge
b. WAN submodule
c. Building distribution
d. Campus core
e. Enterprise branch
f. Enterprise data center

Answer: E. The infrastructure at the remote site usually consists of a WAN router and a small LAN switch.

Q35. Which three types of servers are placed in the e-commerce submodule?
a. Web
b. Application
c. Database
d. Intranet
e. Internet
f. Public share

Answer: A, B, and C. Web, application, and database servers are placed in the e-commerce submodule.

Use Below Figure to answer questions 36–41.


Q36. Which is the campus core layer?

Answer: Block 4.

Q37. Which is the enterprise edge?

Answer: Block 1.

Q38. Which is the campus access layer?

Answer: Block 6.

Q39. Which is the enterprise edge distribution?

Answer: Block 2.

Q40. Which is the campus distribution layer?

Answer: Block 5.

Q41. Which is the campus data center?

Answer: Block 3.

Q42. Which solution supports the enterprise teleworker?
a. IP telephony
b. Enterprise campus
c. Cisco virtual office
d. SP edge
e. Hierarchical design
f. Data Center 3.0

Answer: C. The Cisco Virtual Office supports the teleworker with router, VPN, and IP telephony.

Q43. Which are two benefits of using a modular approach?
a. Simplifies the network design
b. Reduces the amount of network traffic on the network
c. Often reduces the cost and complexity of the network
d. Makes the network simple by using full mesh topologies

Answer: A and C

Q44. Which three modules provide infrastructure for remote users? (Select three.)
a. Teleworker module
b. WAN module
c. Enterprise branch module
d. Campus module
e. Enterprise data center
f. Core, distribution, access layers

Answer: A, C, and E. The teleworker, branch, and data center modules are part of the enterprise remote modules.

Q45. Which are borderless networks infrastructure services? (Select three.)
a. IP telephony
b. Security
c. QoS
d. SP edge
e. High availability
f. Routing

Answer: B, C, and E. Security, QoS, and high availability are borderless network infrastructure services.

Q46. Which module contains devices that supports AAA and stores passwords?
a. WAN module
b. VPN module
c. Server farm module
d. Internet connectivity module
e. SP edge

Answer: C. Servers are located in the server farm module of the enterprise campus area.

Q47. Which topology is best used for connectivity in the building distribution layer?
a. Full mesh
b. Partial mesh
c. Hub and spoke
d. Dual ring
e. EthernetChannel

Answer: B. Partial-mesh connectivity is best suited in the distribution layer.

Q48. What are two ways that wireless access points are used? (Choose two.)
a. Function as a hub for wireless end devices
b. Connect to the enterprise network
c. Function as a Layer 3 switch for wireless end devices
d. Provide physical connectivity for wireless end devices
e. Filter out interference from microwave devices

Answer: A and B. Wireless APs function as a hub to connect wireless end devices to the network.

Q49. In which ways does application network services helps resolve application issues?
a. It can compress, cache, and optimize content.
b. Optimizes web streams which can reduce latency and offload the web server.
c. Multiple data centers increases productivity.
d. Improves application response times by using faster servers.

Answer: A and B

Q50. Which are key features of the distribution layer?
a. Aggregates access layer switches
b. Provides a routing boundary between access and core layers
c. Provides connectivity to end devices
d. Provides fast switching
e. Provides transport to the enterprise edge
f. Provides VPN termination

Answer: A, B, and C

Q51. Which Cisco solution allows a pair of switches to act as a single logical switch?
b. VSS
c. STP
d. GLB

Answer: B. VSS allows a Catalyst 6500 switch pair to act as a single logical switch.

Q52. Which module or layer connects the server layer to the enterprise edge?
a. Campus distribution layer
b. Campus data center access layer
c. Campus core layer
d. Campus MAN module
e. WAN module
f. Internet connectivity module

Answer: C

Q53. Which server type is used in the Internet connectivity module?
a. Corporate
b. Private
c. Public
d. Internal
e. Database
f. Application

Answer: C

Q54. Which server types are used in the e-commerce module for users running applications and storing data? (Select three.)
a. Corporate
b. Private
c. Public
d. Internet
e. Database
f. Application
g. Web

Answer: E, F, and G

Q55. Based on Figure, and assuming that devices may be in more than one layer, list which devices are in each layer.
Access layer:
Distribution layer:

Answer: Access layer: A, D, E, F
Distribution layer: A, C, E, F
Core: B

Use Below Figure 2-21 to answer questions 56–58.


Q56. Which section(s) belong to the core layer?

Answer: Only section B.

Q57. Which section(s) belong to the distribution layer?

Answer: Only section C.

Q58. Which section(s) belong to the access layer?

Answer: Sections A, D, and E belong to the access layer.

Q59. Which Cisco tool enables you to analyze interface statistics, review routing table sizes, and get a performance snapshot of the current network?

Answer: The Netsys Enterprise/Solver performance tool

Q60. Identify three categories that are considered to be administrative data to help characterize the customer’s network.

Answer: The answer can be any combination of three of the following answers:

  • Business Goals
  • Corporate Structure
  • Geographical Structure
  • Current and Future Staffing, Policies, and Politics

Q61. What product can be used as a traffic analysis and protocol analysis tool?

Answer: Sniffer

Q62. What feature of the network design are you trying to include when you discuss future business goals with your customer?

Answer: Scalability

Q63. During your characterization of the network, you realize that WAN implementations and LAN networks are managed by different groups. During which data collection stage would you note this information?

Answer: This is a political issue because changes requested by one group that can potentially affect the other must be identified. Note this information when determining the policies and politics when you are assessing the customer’s corporate profile information.

Q64. Broadcast/multicast behavior, supported frame sizes, flow control, and windowing are all examples of characterizing what type of behavior?

Answer: Traffic behavior

Q65. What is the maximum number of recommended workstations that a flat AppleTalk network could support?

Answer: 200

Q66. True or False: Using the largest frame size that is supported by a medium has a negative impact on network performance.

Answer: False. Ideally, you would want to make sure that the frame size is at the maximum supported limit of the network medium.

Q67. Identify the port used by a protocol such as SMTP.

Answer: Port 25

Q68. What is the purpose in documenting response time to understand and identify performance issues?

Answer: Understanding response time will determine how much time it takes the network to respond to a request for a service.

Q69. True or False: Gathering budget information and resource availability for a project is a part of the process in which you are defining the manageability requirements.

Answer: False. It is a part of the business constraint defining process.

Q70. What is the maximum number of buffer misses a Cisco router can have in an hour?

Answer: 25

Q71. After adding the new print server to the network, you see that the workstations are experiencing performance issues. What is a likely cause of this problem?

Answer: The print server could be advertising its services, thereby sending a lot of broadcast traffic.

Q72. What tool could you use to verify your answer to question #1?

Answer: Use a protocol analyzer on that segment, and see what type of traffic is generated and by what device.

Q73. The customer wants to determine the maximum number of multimedia workstations that should populate a segment. What information do you need to request to find out an approximate number?

Answer: You need to determine the type of LAN protocol used—IP, IPX, AppleTalk, NetBIOS, or mixed.

Q74. Which network devices are used in creating separate segments to decrease workstation broadcasts?

Answer: Routers and switches that have VLAN capability

Q75. During the planning stage, the customer wants a 30 percent improvement on the response his users get from the database. During which phase of extracting the new customer requirements would you address this information?

Answer: The customer has provided a requirement for the new network. During step 6, identify performance requirements, you would note this type of information.

Q76. The customer is concerned about the Token Ring traffic on his network and wants to prove that the Token Ring network must be upgraded. What is your recommendation based on finding out that the Token Ring segment has more than 60 percent utilization?

Answer: The threshold for a Token Ring network is that each segment does not exceed 70 percent. Therefore, you should recommend segmentation of the network.

Q77. Which Cisco IOS command would you use to determine if there were any output queue drops?

Answer: show interface

Q78. When helping to determine the network’s health, would having 25 percent of multicasts on one segment be considered healthy?

Answer: This is unhealthy. It is recommended that none of the segments exceed 20 percent broadcasts/multicasts.

Q79. What is the saturation threshold for WAN links?

Answer: No more than 70 percent utilization

Q80. What tool would you use to help monitor the switching traffic?

Answer: NetFlow

Q81. In which bridging environment does the frame contain the routing information to the destination?

Answer: Source-route bridging (SRB). SRB frames contain a routing information field (RIF) that has routing descriptors to the destination.

Q82. Which scheme provides a way to automatically assign IP addresses to devices on the network?

Answer: Dynamic Host Configuration Protocol (DHCP). With DHCP, clients are assigned an IP address, a subnet mask, and a default gateway by a DHCP server.

Q83. Which session layer protocol is very common in Windows NT environments and can be bridged or routed over IP?

Answer: NetBIOS

Q84. With which Novell protocol do devices broadcast services to the segment, routers build a table and forward these broadcasts to all other segments, and clients use the information to know what services are available in the network?

Answer: Service Advertising Protocol (SAP)

Q85. In what protocol environment do client devices automatically select a network layer address and broadcast a probe to ensure that it is unique?

Answer: AppleTalk

Q86. What are route descriptors?

Answer: Route descriptors are bridge/ring number fields in a routing information field. They are used to set the path that a frame should take on a source-route bridged network.

Q87. With what technology can you scale SRB networks over WAN links and reduce NetBIOS queries where TCP is used between peers?

Answer: Data-link switching (DLSw). DLSw is used to establish a TCP link between remote routers to transport System Network Architecture (SNA) and NetBIOS traffic.

Q88. What is the most scalable protocol used for file and print sharing in Windows NT networking?

Answer: NetBIOS over TCP/IP is more scalable than NetBIOS over NetBUEI.

Q89. What methods are used to assign an IP address to a workstation at bootup?

Answer: DHCP and BOOTP

Q90. What are the three components of a typical firewall system?

Answer: The three components of a typical firewall system are an outside filtering router, an isolation LAN with bastion hosts, and an inside filtering router.

Q91. What session layer protocol is common in Windows NT environments when layered over TCP it can be routed?

Answer: NetBIOS

Q92. You can find WWW and FTP servers in what network that the Internet community can access?

Answer: Isolation LAN

Q93. What is a method to reduce Novell SAP broadcast traffic on the network?

Answer: Use Enhanced IGRP, SAP filters, and NLSP.

Q94. HTTP is an example of what type of traffic flow?

Answer: Client/server

Q95. What access list would you use on an outside filtering router to permit access to the isolation LAN? Assume the isolation LAN is

Answer: access-list 101 ip permit

Q96. What Token Ring field consists of route descriptors?

Answer: Routing information field (RIF)

Q97. What should you use to overcome the limitations of SRB in large networks?

Answer: Data-link switching over an IP network.

Q98. The Cisco PIX Firewall may be used to do what?

Answer: Perform Network Address Translation. Protect the internal network. Provide additional security.

Q99. What service is used to resolve NetBIOS names to IP addresses?

Answer: WINS

Q100. What access list would you use on an internal filtering router to permit traffic between the isolation LAN and the internal network? Assume the isolation LAN is

Answer: access-list 101 ip permit any

Q101. What technique is used to reduce the amount of repetitive unicast traffic?

Answer: Multicast routing

Q102. What type of traffic flow is how small-bandwidth keyboard character streams are sent to the host?

Answer: Terminal/host

Q103. What is a logical grouping of nodes in AppleTalk to control broadcasts?

Answer: AppleTalk zone

Q104. What are examples of client/server traffic flow applications?

Answer: Windows NT networking, Novell, HTTP, and AppleShare are all examples of client/server traffic flow.

Q105. With this technology a user may connect a laptop to the network and automatically have

Answer: an IP address, subnet mask, default gateway, DNS server, and WINS server assigned. DHCP

Q106. DHCP stands for what?

Answer: Dynamic Host Configuration Protocol

Q107. What are route descriptors?

Answer: Route descriptors are bridge ring number fields in a routing information field; they are used to set the path that a frame should take on a source-route bridged network.
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