CCDA FAQ: WAN Design

CCDA FAQ: WAN Design

Q1. What type of WAN technology provides a dedicated connection from the service provider?
a. Circuit-switched data connection
b. Leased lines
c. Packet switched
d. Cell switched

Answer: B. Leased lines are dedicated network connections provided by the service provider.

Q2. What type of topology suffers from a single point of failure?
a. Hub-and-spoke topology
b. Full-mesh topology
c. Partial-mesh topology
d. None of the above

Answer: A. A major disadvantage of the hub and spoke topology is that the hub router represents a single point of failure.

Q3. What kind of topology requires that each site be connected to every other site in the cloud?
a. Hub-and-spoke topology
b. Full-mesh topology
c. Partial-mesh topology
d. All of the above

Answer: B. Full-mesh topologies require that each site has a connection to all other sites in the WAN cloud.

Q4. Which two of the following best describe WAN backup over the Internet deployments?
a. Private WAN
b. Redundancy for primary WAN connection
c. VPLS
d. Best-effort performance

Answer: B and D. WAN backup over the Internet is best effort and provides redundancy for the primary WAN connection.

Q5. Which VPN application gives users connectivity over shared networks?
a. Intranet VPN
b. Extranet VPN
c. Access VPN
d. None of the above

Answer: C. Access VPN connections give users connectivity over shared networks such as the Internet to their corporate intranets.

Q6. What are three types of WAN topologies that can be used with Cisco enterprise architectures in the WAN?
a. Ring
b. Full mesh
c. Partial mesh
d. Hub and spoke

Answer: B, C, and D. Full mesh, partial mesh, and hub and spoke are all WAN topologies used with Cisco enterprise architectures in the WAN.

Q7. The service provider plays an active role in enterprise routing with what kind of VPNs?
a. VPDNs
b. Peer to peer
c. L2TP
d. L2F

Answer: B. With peer-to-peer VPNs, the server provider plays an active role in enterprise routing.

Q8. Which backup option provides an additional virtual circuit for use if needed?
a. Secondary WAN link
b. Shadow PVC
c. Dial backup
d. Load sharing

Answer: B. Service providers can offer shadow PVCs, which provide additional permanent virtual circuits (PVC) for use if needed.

Q9. Which WAN backup option uses load sharing in addition to providing backup services?
a. Dial backup
b. Shadow PVC
c. Secondary WAN link
d. ISDN with DDR

Answer: C. A secondary WAN links provide advantages that include backup WAN services and load sharing.

Q10. What of the following best describes the difference between a small branch and a medium branch?
a. Small branches use dual external switches.
b. Medium branches use single ASA firewall.
c. Small branches use single ASA firewall.
d. Medium branches use external L2 switches.

Answer: D. Medium branches use dual routers and dual external L2 switches.

Q11. How many users are supported in a large branch design?
a. Up to 50
b. Between 50 to 100
c. Between 100 to 1000
d. Between 200 to 5000

Answer: C. Large branches support between 100 and 1000 users.

Q12. What two methods are used to enable private networks over public networks?
a. IPsec
b. PKI
c. GRE
d. PSTN

Answer: A and C. IPsec and GRE are methods that exist for tunneling private networks over a public IP network.

Q13. What is not a factor for WAN architecture selection?
a. Ease of management
b. Ongoing expenses
c. Spanning-tree inconsistencies
d. High availability

Answer: C. Factors for WAN architecture selection include ongoing expenses, ease of management, and high availability.

Q14. Which Layer 3 tunneling technique enables basic IP VPNs without encryption?
a. GRE
b. IPsec
c. IPsec
d. IKE

Answer: A. GRE provides simple Layer 3 tunneling for basic IP VPNs without using encryption.

Q15. Which of the following is not recommended approach for designing WANs?
a. Analyze customer requirements
b. Characterize the existing network
c. Design the new WAN
d. Implement new WAN

Answer: D. Implementing the WAN is not part of the design process.

Q16. What MAN/WAN architecture uses the Internet with site-to-site VPNs?
a. Private WAN
b. ISP service
c. SP MPLS/IP VPN
d. Private WAN with self-deployed MPLS

Answer: B. ISP service uses Internet-based site-to-site VPNs.

Q17. Which WAN backup method does not use the Internet as a transport?
a. IPsec tunnel
b. GRE tunnel
c. Shadow PVC
d. GET VPN

Answer: C. The shadow PVC uses private WAN Frame Relay services.

Q18. What branch design uses ASA firewalls? Select all that apply.
a. Small branch
b. Medium branch
c. Large branch
d. Secure branch

Answer: C. The large branch uses dual router and dual ASA firewalls.

Q19. What WAN/MAN architecture is usually reserved for large enterprises that are willing to make substantial investments in equipment and training?
a. Private WAN
b. Private WAN with self-deployed MPLS
c. ISP service
d. SP MPLS/IP VPN

Answer: B. A private WAN with self-deployed MPLS is usually reserved for large enterprises that are willing to make substantial investments in equipment and training to build out the MPLS network.

Q20. Match each branch profile design with its description.
a. Small branch
b. Medium branch
c. Large branch
d. Enterprise teleworker
i. Single access router
ii. Cable modem router
iii. Pair of access routers
iv. Pair of firewalls

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

Q21. Which of the following are examples of packet- and cell-switched technologies used in the enterprise edge?
a. Frame Relay and ATM
b. ISDN and T1
c. Cable and DSL
d. Analog voice and T1

Answer: A. Frame Relay and ATM are commonly used to connect to WAN services in the enterprise edge.

Q22. Typical remote-access network requirements include which of the following? (Select all that apply.)
a. Best-effort interactive and low-volume traffic patterns
b. Voice and VPN support
c. Connections to the enterprise edge using Layer 2 WAN technologies
d. Server load balancing

Answer: A, B, and C. Typical remote-access requirements include best-effort interactive traffic patterns.

Q23. Which VPN infrastructure is used for business partner connectivity and uses the Internet or a private infrastructure?
a. Access VPN
b. Intranet VPN
c. Extranet VPN
d. Self-deployed MPLS VPN

Answer: C. Extranet VPN infrastructure uses private and public networks, which are used to support business partner connectivity.

Q24. What IPsec technology in the enterprise uses routers along with NHRP and mGRE?
a. IPsec direct encapsulation
b. Easy VPN
c. GET VPN
d. DMVPN

Answer: D. DMVPN. In enterprise environments, DMVPN is used on routers with NHRP and mGRE.

Q25. What backup option allows for both a backup link and load-sharing capabilities using the available bandwidth?
a. Dial backup
b. Secondary WAN link
c. Shadow PVC
d. IPsec tunnel

Answer: B. Secondary WAN links offer both backup and load-sharing capabilities.

Q26. Which common factor is used for WAN architecture selection that involves eliminating single points of failure to increase uptime and growth?
a. Network segmentation
b. Ease of management
c. Redundancy
d. Support for growth

Answer: C. The goal of high availability is to remove the single points of failure in the design, either by software, hardware, or power. Redundancy is critical in providing high levels of availability.

Q27. What WAN/MAN architecture is provided by the service provider and has excellent growth support and high availability?
a. Private WAN
b. ISP service
c. SP MPLS/IP VPN
d. Private MPLS

Answer: C. SP MPLS MPLS/IP VPN has excellent growth support and high-availability services.

Q28. Which Cisco IOS software family has been designed for low-end to mid-range LAN switching?
a. IOS T Releases 12.3, 12.4, 12.3T, and 12.4T
b. IOS S Releases 12.2SE and 12.2SG
c. IOS XR
d. IOS SX

Answer: B. Cisco IOS S Releases 12.2SB and 12.2SR are designed for the enterprise and SP edge networks.

Q29. When designing enterprise branch architecture, which of the following are common network components? (Select all that apply.)
a. Routers supporting WAN edge connectivity
b. Switches providing the Ethernet LAN infrastructure
c. Network management servers
d. IP phones

Answer: A, B, and D. Common components used when designing enterprise branch architectures include routers, switches, and IP phones.

Q30. Which branch design supports 50 to 100 users and provides Layer 3 redundancy features?
a. Small branch
b. Medium branch
c. Large branch
d. Enterprise teleworker

Answer: B. The medium branch design is recommended for branch offices of 50 to 100 users, with an additional access router in the WAN edge allowing for redundancy services.

Q31. Which WAN transport technologies use packet switching to transfer data?

Answer: Frame Relay and X.25

Q32. What is the line speed of a T3 leased line?

Answer: 44.736 Mbps

Q33. The Cisco Product Selection Tool can be found where?

Answer: The Cisco Web site (www.cisco.com) or the Cisco documentation CDROM

Q34. If a customer is concerned about the cost of a WAN network, what technology would you recommend for a backup connection to a 128-Kb leased line?

Answer: An ISDN line. An ISDN line is a common cost-effective backup solution because the customer pays on a per use basis and has minimal equipment fees. Based on the line speed, ISDN can easily support the 128-Kb requirement.

Q35. What are the two criteria for a good WAN design?

Answer: Minimize the cost of the bandwidth and optimize the efficient use of the bandwidth.

Q36. Identify the switching method on the router that has the following qualities: an inbound

Answer: access list, high CPU utilization, and compression of packets. Process switching

Q37. Which devices support optimum switching?

Answer: Optimum switching is available only on a Route Switch Processor (RSP).

Q38. How many DS0s are there in a T1 line?

Answer: 24

Q39. What class of Cisco routers is a 2600?

Answer: Access router

Q40 What is the first step in provisioning a Frame Relay circuit?

Answer: Determine what the committed information rate (CIR) needs to be, based on the traffic that will use the data connection.

Q41. How many DS0s are needed to form a T1 line?

Answer: 24 DS0s are needed. A T1 is equal to 1.544 Mbps and is a common line speed used to provide Internet access.

Q42. When using Frame Relay, which Cisco IOS version would best support a Voice over Frame Relay (VoFR) implementation?

Answer: Cisco IOS Release 11.2, because it supports Frame Relay traffic shaping, which has features to enhance the performance of the permanent virtual circuit (PVC).

Q43. Which traffic shaping feature would best support the VoFR implementation?

Answer: The enhanced queuing support on a per virtual circuit basis would provide queuing capability. This would guarantee bandwidth for the voice implementation so that the traffic would not be disrupted.

Q44. When determining the Frame Relay CIR for the central office, the CCDA reviews all the traffic from the remote offices that needs to be transferred to the central office. Which step in provisioning a Frame Relay network would help determine how much bandwidth is required?

Answer: Step 2: Aggregate all the CIRs to determine core bandwidth requirements. The CIR needed will depend on the total of CIRs from each remote office to transfer data with the central office.

Q45. Which switching method matches packets with its route cache?

Answer: Fast switching uses this method of comparing incoming packets with an entry in its fast-switching cache.

Q46. Which WAN technology uses the Public Switched Telephone Network (PSTN)?

Answer: An analog modem uses the existing phone system, also known as plain old telephone service (POTS).

Q47. What term is used to describe the process of passing a packet internally from one router’s interface to the other?

Answer: Switching

Q48. Which packet-switching technology is used on unreliable WAN connections?

Answer: X.25 has data correcting and error checking overhead. It is used on WAN connections that are often unreliable.

Q49. Frame Relay uses which two layers of the OSI model?

Answer: The physical and data-link layers

Q50. What router component would be used on a 2600 to provide an integrated CSU/DSU for a T1 connection?

Answer: WAN interface card

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