Review Questions
Which of the following are alternate representations of the decimal number 227? Choose two.
- A. 0x227
- B. 11100011
- C. 0x143
- D. 0xE3
- E. 11100110
Which of the following are alternate representations of 0xB8? Choose two.
- A. 10110100
- B. 10111111
- C. 10111000
- D. 184
- E. 0x184
You have been asked to create a subnet that supports 16 hosts. What subnet mask should you use?
- A. 255.255.255.252
- B. 255.255.255.248
- C. 255.255.255.240
- D. 255.255.255.224
Given the mask 255.255.254.0, how many hosts per subnet does this create?
- A. 254
- B. 256
- C. 512
- D. 510
- E. 2
You are a senior network engineer at True North Technologies. Your boss, Mr. Martin, asks you to create a subnet with room for 12 IPs for some new managers. Mr. Martin promises that there will never be more than 12 managers, and he asks you to make sure that you conserve IP address space by providing the minimum number of possible host IPs on the subnet. What subnet mask will best meet these requirements?
- A. 255.255.255.12
- B. 255.255.255.0
- C. 255.255.240.0
- D. 255.255.255.240
- E. 255.255.255.224
Your boss, Duncan, does not seem to be able to grasp subnetting. He comes out of a management meeting and quietly asks you to help him with a subnetting issue. He needs to divide the Class B address space the company uses into six subnets for the various buildings in the plant, while keeping the subnets as large as possible to allow for future growth. What is the best subnet mask to use in this scenario?
- A. 255.255.0.0
- B. 255.255.248.0
- C. 255.255.224.0
- D. 255.255.240.0
- E. 255.255.255.224
You have purchased several brand-new Cisco routers for your company. Your current address space is 172.16.0.0 /22. Because these new routers support the ip subnet zero command, you realize you are about to gain back two subnets that you could not use with the old gear. How many subnets total will be available to you once the upgrades are complete?
- A. 4
- B. 2
- C. 32
- D. 62
- E. 64
Which of the following are true about the following address and mask pair: 10.8.8.0 /24? Assume that all subnets are available. Choose all that apply.
- A. This is a Class B address.
- B. This is a Class A address.
- C. This is a Class C address.
- D. 16 bits were stolen from the host field.
- E. 24 bits were stolen from the host field.
- F. The default mask for this address is 255.0.0.0.
- G. The mask can also be written as 255.255.255.0.
- H. The mask creates 65,536 subnets total from the default address space.
- I. Each subnet supports 256 valid host IPs.
- J. Each subnet supports 254 valid host IPs.
Indy and Greg have configured their own Windows 8 PCs and connected them with crossover cables. They can’t seem to share their illegally downloaded MP3 files, however. Given their configurations, what could be the problem?
Indy’s configuration:
IP: 192.168.0.65
Mask: 255.255.255.192
Greg’s configuration:
IP: 192.168.0.62
Mask: 255.255.255.192
- A. Indy is using a broadcast ID for his IP.
- B. Greg is using an invalid mask.
- C. Indy’s IP is in one of the zero subnets.
- D. Greg and Indy are using IPs in different subnets.
You are given an old router to practice for your CCNA. Your boss, Dave, has spent a lot of time teaching you subnetting. Now he challenges you to apply your knowledge. He hands you a note that says the following:
“Given the subnetted address space of 192.168.1.0 /29, give the E0 interface the first valid IP in the eighth subnet. Give the S0 interface the last valid IP in the 12th subnet. The zero subnets are available. You have 10 minutes. Go.”
Which two of the following are the correct IP and mask configurations? Choose two.
- A. E0: 192.168.1.1 255.255.255.0
- B. E0: 192.168.1.56 255.255.255.248
- C. E0: 192.168.1.57 255.255.255.248
- D. S0: 192.168.1.254 255.255.255.0
- E. S0: 192.168.1.95 255.255.255.248
- F. S0: 192.168.1.94 255.255.255.248
The following questions are part of a Subnetting SuperChallenge. This monster question will stretch your subnetting skills, especially if you give yourself a time limit. Start with 10 minutes and see if you can get down to 5.
The Vancouver Sailing Company has four locations: a head office and three branch offices. Each of the branches is connected to the head office by a point-to-point T1 circuit. The branches have one or more LANs connected to their routers. The routers are called Main, Jib, Genoa, and Spinnaker. The company has been assigned the 172.16.0.0/20 address space to work within.
Your task is to choose the correct IP address and mask for each interface, based on the information provided. Remember that no IP address may overlap with any address in another subnet, and that the required number of hosts for each subnet will affect your decision as to which address to use.
Here are the known IP configurations for the routers:
Main:
S0/0:172.16.0.1 /30
S0/1:172.16.0.5 /30
S0/2:172.16.0.9 /30
Fa1/0:172.16.4.1 /23
Fa1/1:172.16.6.1 /23
Jib:
S0/0: Connects to Main S0/0
Fa1/0: 172.16.8.33/27
Fa1/1: 30 hosts needed
Genoa:
S0/0: Connects to Main S0/1
Fa1/0: 172.16.8.129/26
Fa1/1: 100 hosts needed
Fa2/0: 100 hosts needed
Fa2/1: 172.16.13.0/24.
Spinnaker:
S0/0: Connects to Main S0/2
Fa1/0: 500 hosts needed
Choose the correct IP and mask assignments for each router:
- A. Jib Fa1/1: 172.16.8.62/27
- B. Jib Fa1/1: 172. 16.8.64/27
- C. Jib Fa1/1: 172.16.8.65/28
- D. Jib Fa1/0: 172.16.8.65/27
- E. Jib Fa1/1: 172.16.8.65/27
- F. Genoa S0/0: 172.16.0.2/30
- G. Genoa S0/0:172.16.0.6/30
- H. Genoa Fa1/1:172.16.12.1/26
- I. Genoa Fa1/1:172.16.12.1/25
- J. Genoa Fa2/0:172.16.12.129/24
- K. Genoa Fa2/0:172.16.12.129/25
- L. Genoa Fa2/1:172.16.12.193/25
- M. Genoa Fa2/1:172.16.13.1/25
- N. Genoa Fa0/2:172.16.13.1/24
- O. Spinnaker S0/0: 172.16.0.10/30
- P. Spinnaker S0/0: 172.16.0.12/30
- Q. Spinnaker Fa1/0: 172.16.13.0/23
- R. Spinnaker Fa1/0: 172.16.14.0/23
- S. Spinnaker Fa1/0: 172.16.14.1/23
Which of the following is the best summary statement for the following range of networks?
192.168.1.0 /24–192.168.15.0 /24
- A. 192.168.1.0
- B. 192.168.1.0 255.255.240.0
- C. 192.168.1.0 0.0.15.0
- D. 192.168.1.0 255.255.248.0
- E. 192.168.0.0 255.255.240.0
Which of the following is the best summary statement for the following range of networks?
192.168.24.0 /24–192.168.31.0 /24
- A. 192.168.24.0 255.255.240.0
- B. 192.168.24.0 /28
- C. 192.168.24.0 /21
- D. 192.168.0.0 /27
Which of the following networks are included in the summary 172.16.0.0 /13? Choose all that apply.
- A. 172.0.0.0 /16
- B. 172.16.0.0 /16
- C. 172.24.0.0 /16
- D. 172.21.0.0 /16
- E. 172.18.0.0 /16
What are the advantages of route summarization? Choose three.
- A. Ensures job security for network admins because of difficulty of configuration
- B. Reduces routing update traffic overhead
- C. Reduces the impact of discontiguous subnets
- D. Reduces CPU and memory load on routers
- E. Identifies flapping interfaces
- F. Hides network instability
Which of the following is a valid IPv6 address format?
- A. G412:AFFA:2001:0000:0000:0000:0000:0001
- B. 2001:8888:EEEE:1010:0000:0000:0000:0001
- C. 2001::8888::1
- D. 2010:2112:5440:1812:1867
Which of the following is a valid IPv6 unicast address format?
- A. 2001:8888:EEEE:1010:0000:0000:0000:0001
- B. FF00:0000:0000:0002:00CO:00A8:0001:0042
- C. 2001:8888::2FFE::00A8
- D. FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF
Which of the following are valid IPv6 address formats for the same address? Choose three.
- A. 2001:0000:0000:0200:0222:0000:0000:0001
- B. 2001:0000:0000:02:0222:0000:0000:0001
- C. 2001:0:0:200:222:0:0:1
- D. 2001::200:222::1
- E. 2001:0:0:200:222::1
Which of the following is a valid IPv6 unicast address?
- A. FF00:2112:1812:5440::1
- B. 1812:2112:5440:1
- C. 255:255:255:255:255:255:255:255:255
- D. None of the above