#### NET 222: Introduction to Routers and Routing

##### Review for Second Test
1. What is a subnet?

2. What are the classful subnet masks for classes A, B, and C?

3. What formula tells you how many subnets can be made in a subnetting problem? What is the difference in the formula when you can and cannot use the IP subnet-zero command?

4. What formula tells you how many hosts can be placed on each subnet you create?

5. When you create a series of subnets, how do you determine the subnet address for each one? How do you determine the broadcast address for each one? How do you determine the range of host addresses for each subnet?

6. Examine this problem, and answer each question using the methods from the chapter or from my notes.
Required number of subnets: 100
Required number of hosts/subnet:400
What is the required subnet mask?
What is the actual number of possible subnets with that mask?
What is the actual number of possible hosts per subnet?
What is the value of delta (block size)?
Fill in this chart for the first four subnets:

7. Examine this problem, and answer each question using the methods from the chapter or from my notes.
What is the CIDR notation for this mask?
What is the actual number of possible subnets with that mask?
What is the actual number of possible hosts per subnet?
What is the value of delta (block size)?
Fill in this chart for the first four subnets:

8. What is VLSM? Why does it allow us to do that classful subnetting does not?

9. What is CIDR notation? What other networking concept can you substitute CIDR notation for?

10. We will make a modification to the Microsoft example of VLSM. Assume a starting network ID of 10.0.0.0/8. You are required to create three subnets with up to 60,000 hosts each, 12 subnets with up to 2,000 hosts each, and eight subnets with up to 250 hosts each. Start with the subnet with the most hosts, and work down.

What is the subnet mask in use when you start this problem?
Can the requirements be met?
What are the steps that can be carried out?

11. When troubleshooting, what series of pings does the text recommend trying?
What might be indicated by a failure at each step?

12. When you create a subnet, what two addresses on that subnet must not be assigned to hosts? Why?