Two years later, your company has changed ISPs again, and the new ISP gave the company a new IP range.  You now must redesign the subnets to meet the needs of each department. However, the routing protocol has recently changed and your router now uses OSPF, which supports VLSM.  Your IP range is now 30.30.30.0/24, and the number of needed IP addresses has changed as well.

What Class of address has the ISP given you?
What is the default subnet mask for that Class?
What subnet mask were you given to use?
Is your range a network unto itself, or a subnet of a larger network?
How many total IP addresses do you have available in the network given to you?

The company has experienced some growth, especially the Sales department. You’ve been given the following information for how many IP addresses each department now needs:

Subnet    Department    # IP addresses
A    Accounting    5
B    Sales    55
D    Inventory    20
E    Management    5
F    Drivers/Loaders    9

Using VLSM design, list the first five valid subnet ranges in the table below.

Subnet    # IP addresses    Subnet ID    Subnet mask    Valid Host IP Range
A    5
B    55
C    20
D    5
E    9