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Chapter 3
Chapter 3
| 1: | Name the four modules that the Enterprise Edge functional area is comprised of. | ||||||||||||||||
| A1: | Answer: E-Commerce, Internet Connectivity, Remote Access and VPN, WAN | ||||||||||||||||
| 2: | Name at least four of the typical requirements for the Enterprise Edge functional area. | ||||||||||||||||
| A2: | Answer: Functionality, performance, scalability, availability, manageability, cost effectiveness | ||||||||||||||||
| 3: | List the eight steps of the Cisco Enterprise Edge Design methodology. | ||||||||||||||||
| A3: | Answer:
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| 4: | Name at least two important characteristics of network applications that need to be noted while analyzing network traffic patterns. | ||||||||||||||||
| A4: | Answer: Minimum bandwidth needed, plus delay, jitter, and loss tolerance | ||||||||||||||||
| 5: | List at least three enterprise requirements for a site-to-site WAN solution. | ||||||||||||||||
| A5: | Answer: Bandwidth, link quality, reliability, data-link protocol characteristics, always-on or on-demand characteristics, cost | ||||||||||||||||
| 6: | What are some of the valid questions for designing a branch office WAN connection? (List at least three.) | ||||||||||||||||
| A6: | Answer:
How many users are in the branch? What are the per-application bandwidth requirements? What is the total bandwidth needed for applications? What type of routing protocol is going to be used? What are the redundancy needs of the site? What is the effect on the business if the site is unreachable or if the site cannot reach the central servers? Is the site supporting on-demand connectivity to other sites or users? | ||||||||||||||||
| 7: | When developing the WAN module to support a regional office WAN, what questions need to be answered? (List at least three.) | ||||||||||||||||
| A7: | Answer:
How many users are in the regional office? What are the per-application bandwidth requirements? What is the total bandwidth needed for applications? What type of routing protocol is going to be used? What are the redundancy needs of the site? What is the effect on the business if the site is not reachable or the site cannot reach the central servers? Is the site supporting on-demand connectivity to other sites or users? Is the site a rally point for traffic from other sites to pass through? Does the regional site have servers or services that are shared with other offices, either branch or core? Does this change the amount of bandwidth that the branch offices need to the core? | ||||||||||||||||
| 8: | What questions/concerns need to be answered/addressed when designing the enterprise WAN backbone? (List at least three.) | ||||||||||||||||
| A8: | Answer:
What are the per-application bandwidth requirements? What is the total bandwidth needed for applications? What type of routing protocol is going to be used? What are the redundancy needs of the site? What is the effect on the business if the site is not reachable? Is the site supporting on-demand connectivity to other sites or users? Is the site a rally point for traffic from other sites to pass through? | ||||||||||||||||
| 9: | Name at least three criteria for selection of a service provider. | ||||||||||||||||
| A9: | Answer: Price, speeds supported, features supported, geographies covered, service level agreements | ||||||||||||||||
| 10: | What are the commonly selected data-link layer WAN technologies? (Name at least two.) | ||||||||||||||||
| A10: | Answer: PPP, Frame Relay, ATM, X.25, and MPLS | ||||||||||||||||
| 11: | What are the commonly selected physical layer WAN technologies? (Name at least two.) | ||||||||||||||||
| A11: | Answer: Leased line, DSL, dial-up, ISDN, and Optical Carrier (SONET/SDH) | ||||||||||||||||
| 12: | Explain the MP feature of PPP. | ||||||||||||||||
| A12: | Answer: Multilink PPP (MP) allows devices to send data over multiple point-to-point data links to the same destination by implementing a virtual link. The MP connection has a maximum bandwidth equal to the sum of the bandwidths of the component links. MP can be configured for either multiplexed links, such as ISDN and Frame Relay, or for multiple asynchronous lines. | ||||||||||||||||
| 13: | Name at least three service classes of ATM. | ||||||||||||||||
| A13: | Answer: CBR, ABR, UBR, RT-VBR, NRT-VBR | ||||||||||||||||
| 14: | What is the name of the online tool Cisco provides for choosing the best Cisco product for your particular needs? | ||||||||||||||||
| A14: | Answer: Product Advisor | ||||||||||||||||
| 15: | Name three routing protocols that are suitable for site-to-site WAN. Which is the most scalable and nonproprietary protocol? | ||||||||||||||||
| A15: | Answer:
Static Routing, EIGRP, and OSPF (IS-IS is also acceptable). OSPF (IS-IS is also a correct answer) is standards based (nonproprietary) and scalable. | ||||||||||||||||
| 16: | When designing the remote-access connectivity, what important questions need to be answered? | ||||||||||||||||
| A16: | Answer:
What type of remote-access is needed? (Site-to-site or individual user remote access) What types of access connectivity is needed in the environment? (Dialup, broadband, or VPN) Where is the remote-access termination point going to be? (Central site, remote site, or service provider) Who is going to provide the actual termination endpoint of the remote access device? | ||||||||||||||||
| 17: | In what situation would an on-demand remote-access solution be viable for a group of employees at a remote site? | ||||||||||||||||
| A17: | Answer:
Sporadic need for enterprise network connectivity, not requiring an “always up” connection Multiple users at a facility sharing the on-demand access Prohibitive cost of installing a dedicated always-on connection | ||||||||||||||||
| 18: | What are some questions to be asked about remote-access physical termination? | ||||||||||||||||
| A18: | Answer:
What are the requirements on the termination ports? Do they have to support voice, data, and fax? What is the cost of bringing all the users into a central site, versus the cost of maintaining modem pools in several sites? Where will the connectivity be most reliable? How many users are going to simultaneously use the remote-access system? Are the users mobile or fixed? How many fixed users have access to always-on technology? Are sites, or individual users, being terminated? | ||||||||||||||||
| 19: | What are five common physical layer technologies (dialup and broadband) for enterprise remote access? | ||||||||||||||||
| A19: | Answer: Modem dialup, ISDN, cell phone, DSL, cable modem | ||||||||||||||||
| 20: | To size the central site remote-access solution, what parameters need to be determined? How would the peak bandwidth be determined? | ||||||||||||||||
| A20: | Answer:
The total number of remote users, percentage of remote users that log in at once, and bandwidth required per user. To determine the peak bandwidth, use the following formula: Total bandwidth required = Total number of remote users * percentage of users logged in at one time (expressed as 0.nn) * bandwidth required per user (expressed as kbps) | ||||||||||||||||
| 21: | To determine Internet connectivity requirements, what are some of the basic questions that must be answered? | ||||||||||||||||
| A21: | Answer:
Does the enterprise need a single Internet connection or multiple Internet connections? Will multiple Internet connections be furnished by a single ISP or by different ISPs? If multiple ISPs are used, how will load balancing be done? Which routing protocol will advertise the Internet internally, and advertise publicly available subnets externally? Is NAT or PAT required at a router or transition device between the public and corporate network? What security measures are required to protect the corporate network? | ||||||||||||||||
| 22: | Name the major forms of NAT. | ||||||||||||||||
| A22: | Answer: Static, dynamic, overloading, overlapping | ||||||||||||||||
| 23: | What are some the common questions that must be asked when implementing a single-homed connection? | ||||||||||||||||
| A23: | Answer:
What are the consequences if the Internet connection is lost? Can the enterprise afford the consequences of an outage? Will public addressing or private addressing be used in the network? If private addressing is used inside, how many public addresses are needed to support the hosts that need static addressing? How many addresses are needed in the address pool for the users? When selecting the ISP, what services and support does it provide? | ||||||||||||||||
| 24: | What are the advantages of multihoming? | ||||||||||||||||
| A24: | Answer: Reliability and availability (fault tolerance), load sharing, and ability to enforce policies. | ||||||||||||||||
| 25: | What are the two routing options for a multihomed solution? | ||||||||||||||||
| A25: | Answer:
Run BGP on edge routers, set them up as IBGP peers, and set up EBGP relation between these routers and their ISP counterparts. Setup static gateways of last resort on the edge routers pointing to the ISPs, and inject gateway of last resort (default route) into the network. |
