Chapter 6 case study

CCNA Exploration: Network Fundamentals  Chapter 6 Case Study
Intro: Another company called ImageNeen Inc. contacted you; they need a network project.

The Scenario: After a quick talk to theImageNeen people, you make a draft of their future topology. The topology is shown below:

Topology:

Since the company will have direct access to the internet, with all its devices using valid IPAddresses, the ISP provided an entire class C IP Address range: 201.25.78.0/24. Because the topology has 17 networks, 17 different IP address ranges must be created. Since the Ethernet segments mustsupport at least 13 hosts, we have: 13 hosts per network = 4 bits on the last octet reserved for hosts which leaves to only 4 bits to create networks. (24 = 16 networks)

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CCNA Exploration: Network Fundamentals  Chapter 6 Case Study
Based on that, you concluded that regular sub-netting processes won’t give enough host addresses/networks to be assigned to thetopology. A more careful analysis shows that even though 17 networks are necessary, not all the 17 networks must have the same number of hosts. The serial links only need 2 valid host addressesbecause there are only 2 devices on that link. A VLSM approach is needed. Variable Length Subnet Mask (VLSM) allows networks with different sizes to coexist within a domain. Your job at ImageNeen is toaddress its computer network based on the following requirements: 1. 2. 3. Each ImageNeen individual internal network (the networks behind internal ImageNeen routers) must support a maximum of 13 UserPCs. All the 17 segments must be addressed. Only the class C range provided by the ISP, 201.25.78.0/24, is available. Use the addresses wisely!

Question 1: a. Which is the most suitable mask for theserial links? b. Which is the most suitable mask for the Ethernet segments?

Question 2: a. Assign the networks you created to the links of the topology shown above.

Answers: 1a. /30 which...