Designing Cisco Network Service Architectures - Free Books

Answer KeyThe recommended solutions for the activities that are described in this guide appear here.Case Study 1 Answer Key: MegaCorp Campus DesignYou will create a high level design for the campus portions of the MegaCorp network includingthe following objectives:• Document and explain the real customer requirements for this scenario.• Complete and present an optimal high-level design, including diagram, physical and logicaltopology descriptions, recommended switch models and alternatives, other significantdetails, notes on how your design will support IP Telephony, and notes on what your Powerover Ethernet (PoE) recommendations are. Describe and defend the pros and cons for youroptimal design, and how it improves on the existing MegaCorp design.• Describe any other technical design factors the detailed design should incorporate.• Present a high-level approach for how to smoothly migrate from the old to the new networkdesign.• Describe how to mitigate risks in the present MegaCorp design using Cisco switches.• Complete and present a design using Metro Ethernet components as provided in this CaseStudy to connect to remote office buildings.Step 1 Real Requirements• If IPT and video are under consideration, the network needs to be highly available and haveplenty of bandwidth.• The stated outage rate and duration is not compatible with “high availability”. Betteravailability is needed.• The long hours of office use suggest productivity and frugality are important to MegaCorp.The network needs to operate 18 x 5, not just 9 x 5.• Good service is hard to provide if customer records cannot be accessed due to a networkoutage. The same is even more so when IPT is in use. Not answering the phone sends thewrong signal to customers. This just emphasizes that reliability and high availability areimportant requirements for MegaCorp.• IPT means the design should use QoS-capable switches.• The access switches need to be PoE-capable on most if not all ports. There should be littleto no need for PoE on distribution and core switches.• The access switches should provide at least 100 Mbps access ports and 1 Gbps uplinks.• The design should be recommended practices compliant. This is both a requirement andsomething you can use as a major justification for appropriate differences from the staffdesign.• Unless there is an unstated good reason for it, there is no reason to tie VLANs todepartments. A follow-up question should clarify this.• Simplicity and ease of troubleshooting would be good.© 2007 Cisco Systems, Inc. Lab Guide 41