CCNA Exam Questions: Subnetting, VLSM, and IPv6
This chapter covers the following ICND2 objectives that fall under the content areas, Implement an IP addressing scheme and IP Services to meet network requirements in a medium-size Enterprise branch office network:
- Calculate and apply a VLSM IP addressing design to a network.
- Determine the appropriate classless addressing scheme using VLSM and summarization to satisfy addressing requirements in a LAN/WAN environment.
- Describe the technological requirements for running IPv6 (including protocols, dual stack, tunneling, and so on).
- Describe IPv6 addresses.
- Identify and correct common problems associated with IP addressing and host configurations.
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Refer to Figure 8.1. The administrator wants to reduce the size of the Central router routing table. Which of the following summary routes would represent all the LANs in Tempe, with no additional subnets?
Figure 8.1 Network diagram.
○ A. 172.16.0.0/24 ○ B. 172.16.0.0/23 ○ C. 172.16.0.0/22 ○ D. 172.16.1.0/24 ○ E. 172.16.1.0/23 ○ F. 172.16.1.0/22 Quick Answer: 175
Detailed Answer: 176
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An Ethernet port on a router in your organization is assigned the IP address 10.65.64.1/21. What is the maximum number of hosts allowed on this subnet?
○ A. 254 ○ B. 510 ○ C. 1022 ○ D. 2046 ○ E. 4094 ○ F. 4096 Quick Answer: 175
Detailed Answer: 176
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Refer to Figure 8.2. All routers in the network have been configured with the ip subnet-zero command. Which subnet addresses should be used for Network A and Network B? (Choose two.)
Figure 8.2 Network diagram.
○ A. Network A – 192.168.1.112/25 ○ B. Network A – 192.168.1.112/26 ○ C. Network A – 192.168.1.128/25 ○ D. Network B – 192.168.1.10/30 ○ E. Network B – 192.168.1.70/30 ○ F. Network B – 192.168.1.0/30 Quick Answer: 175
Detailed Answer: 176
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Which of the following are invalid IPv6 communication types? (Choose two.)
○ A. Unicast ○ B. Multicast ○ C. Broadcast ○ D. Anycast ○ E. Cryptocast Quick Answer: 175
Detailed Answer: 176
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Which of the following are valid IPv6 addresses? (Choose three.)
○ A. 2001:0db8:0000:0000:0000:0000:1428:57ab ○ B. 2001:0db8::1428:57ab ○ C. 2001::1685:2123::1428:57ab ○ D. 2001:99:ab:1:99:2:1:9 ○ E. 2001:1428:57ab:1685:2123:1428:57ab Quick Answer: 175
Detailed Answer: 176
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A router that is running both IPv4 and IPv6 addressing on the same interface is known as what type of router?
○ A. 6to4 ○ B. 4to6 ○ C. NAT-PT ○ D. 4to6 tunneling ○ E. Dual-stack Quick Answer: 175
Detailed Answer: 176
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RouterA is acting as an OSPF ABR between Area 1 and Area 0 as shown in Figure 8.3. Your organization wants to implement route summarization capabilities between these two areas. Which of the following describe the most efficient route summarization possibilities? (Choose two.)
Figure 8.3 Network diagram.
Quick Answer: 175
Detailed Answer: 177
○ A. OSPF Area 0 – 10.170.0.0/16 ○ B. OSPF Area 0 – 10.170.112.0/21 ○ C. OSPF Area 0 – 10.170.112.0/20 ○ D. OSPF Area 0 – 10.170.112.0/22 ○ E. OSPF Area 0 – 10.170.120.0/22 ○ F. OSPF Area 1 – 10.170.0.0/16 ○ G. OSPF Area 1 – 10.170.0.0/21 ○ H. OSPF Area 1 – 10.170.0.0/22 ○ I. OSPF Area 1 – 10.170.0.0/23 Quick Answer: 175
Detailed Answer: 177
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You are designing an IP address scheme for your new remote office. The vice president of IT calls to tell you that you will be in charge of the 192.168.1.64/26 subnetwork. This supplies you with a single subnetwork with 62 hosts. You need to have at least four subnets with 14 hosts in each subnet. What custom subnet mask should you use?
○ A. 255.255.255.128 ○ B. 255.255.255.192 ○ C. 255.255.255.224 ○ D. 255.255.255.240 ○ E. 255.255.255.248 Quick Answer: 175
Detailed Answer: 177
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Identify three valid host addresses in any subnet of the 201.168.27.0 network, assuming a fixed subnet mask of 255.255.255.240. (Choose three.)
○ A. 201.168.27.33 ○ B. 201.168.27.112 ○ C. 201.168.27.119 ○ D. 201.168.27.126 ○ E. 201.168.27.175 ○ F. 201.168.27.208 Quick Answer: 175
Detailed Answer: 177
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A new network is being designed for your company, Acme, Inc. If you use a Class C IP network, which subnet masks will provide one usable subnet per department while allowing enough usable host addresses for each department specified in the table? (Choose three.)
Department
Number of Users
Corporate
117
Customer Support
15
Financial
25
HR
5
Engineering
5
○ A. 255.255.255.0 ○ B. 255.255.255.128 ○ C. 255.255.255.192 ○ D. 255.255.255.224 ○ E. 255.255.255.240 ○ F. 255.255.255.248 ○ G. 255.255.255.252 Quick Answer: 175
Detailed Answer: 178
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You are troubleshooting your router's interfaces. For some reason, the Ethernet interface will not accept the IP address of 192.168.5.95/27 that you've assigned. Which of the following explains the router's refusal to take the IP address?
○ A. Class C addresses cannot be assigned to Ethernet interfaces. ○ B. The /27 is an invalid mask. ○ C. It is a broadcast address. ○ D. It is a network address. ○ E. It is a public address. ○ F. It is a private address. Quick Answer: 175
Detailed Answer: 178
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Your organization has moved to IPv6 addressing. The corporate office is connected to the two branch offices through the Internet, as shown in Figure 8.4. What tunneling type is this organization using?
Figure 8.4 Network diagram.
○ A. IPv6 VPN ○ B. 6to4 tunneling ○ C. 4to6 tunneling ○ D. NAT-PT, VPN based Quick Answer: 175
Detailed Answer: 178
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Your organization has opened a new branch office, as shown in Figure 8.5. The corporation uses 10.0.0.0/8 addressing and wants to use 172.16.X.X/24 address blocks for the branch offices. The new branch office will be large enough to require two of these blocks. Which two blocks will be easily summarizable to a single routing table entry? (Choose two.)
Figure 8.5 Network diagram.
○ A. 172.16.111.0/24 ○ B. 172.16.112.0/24 ○ C. 172.16.113.0/24 ○ D. 172.16.165.0/24 ○ E. 172.16.166.0/24 Quick Answer: 175
Detailed Answer: 178
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Widget, Inc., uses the Class B address 172.30.0.0/16 to address its organization. The western region of the organization (shown in Figure 8.6) has been allocated the 172.30.32.0/20 block. As the administrator of the Phoenix office, you are required to allocate valid subnets to the HQ and three branch offices shown in Figure 8.6. Draw lines showing the subnet that should be assigned to each office. All answers will not be used.
Figure 8.6 Network diagram.
Quick Answer: 175
Detailed Answer: 179
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Which of the following routing protocols support VLSM capabilities? (Choose three.)
○ A. RIP ○ B. RIPv2 ○ C. EIGRP ○ D. IGRP ○ E. OSPF Quick Answer: 175
Detailed Answer: 179
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XYZ Company has constructed the network shown in Figure 8.7. The company currently is using EIGRP with auto-summarization features enabled. How will routers in the corporate network see the 172.16.x.x networks behind R1?
Figure 8.7 Network diagram.
○ A. Networks behind R1 will be summarized into a single 172.16.0.0/16 entry. ○ B. Networks behind R1 will be summarized into a single 172.16.0.0/21 entry. ○ C. The /24 networks behind R1 will be auto-summarized into a single 172.16.0.0/16 entry. The /30 WAN link networks will be auto-summarized into a single 172.16.2.0/24 entry. ○ D. The /24 networks behind R1 will be auto-summarized into a single 172.16.0.0/21 entry. The /30 WAN link networks will be auto-summarized into a single 172.16.2.0/24 entry. ○ E. EIGRP cannot handle VLSM configurations with auto-summarization enabled. This network will experience connectivity issues. Quick Answer: 175
Detailed Answer: 179
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An IPv6 address is a _____-bit address.
○ A. 16 ○ B. 32 ○ C. 64 ○ D. 128 ○ E. 256 Quick Answer: 175
Detailed Answer: 179
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In IPv6, Internet-valid addresses are known by what name?
○ A. Private ○ B. Public ○ C. Unique ○ D. Unspecified ○ E. Global Quick Answer: 175
Detailed Answer: 179
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In IPv6, a ___________ address is used to communicate with hosts on the directly attached network and will never forward beyond the first router hop.
○ A. Global ○ B. Private ○ C. Link local ○ D. Private restricted ○ E. Auto-generated Quick Answer: 175
Detailed Answer: 180
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Which of the following commands could you use to assign an IPv6 address to your router?
○ A. Router(config-if)#ip address fe01:3112:abcd::0001 255.255.255.0 ○ B. Router(config-if)#ip address fe01:3112:abcd::0001/48 ○ C. Router(config-if)#ip address 6 fe01:3112:abcd::0001 255.255.255.0 ○ D. Router(config-if)#ip address 6 fe01:3112:abcd::0001/48 ○ E. Router(config-if)#ipv6 address fe01:3112:abcd::0001 255.255.255.0 ○ F. Router(config-if)#ipv6 address fe01:3112:abcd::0001/48 Quick Answer: 175
Detailed Answer: 180
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Which of the following commands could you use to start a RIPng process on your router?
○ A. Router(config)#router RIPng ○ B. Router(config)#ipv6 router rip RIPng ○ C. Router(config)#routerv6 RIP ○ D. Router(config)#ripv6 Quick Answer: 175
Detailed Answer: 180
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TooCow University has acquired the 150.60.130.0/24 public address from the local ISP to use in its campus network. Each building has a specific number of devices that are required to be publicly accessible, as shown in Figure 8.8. Which of the following subnets would accommodate the network shown? (Choose four.)
Figure 8.8 Network diagram.
○ A. 150.60.130.128/26 ○ B. 150.60.130.128/27 ○ C. 150.60.130.96/27 ○ D. 150.60.130.192/28 ○ E. 150.60.130.32/27 ○ F. 150.60.130.160/27 ○ G. 150.60.130.16/28 ○ H. 150.60.130.0/25 Quick Answer: 175
Detailed Answer: 180
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Choose the most efficient summary address to encompass the following subnets:
- 192.168.112.0/24
- 192.168.113.0/24
- 192.168.114.0/24
- 192.168.115.0/24
- 192.168.116.0/24
- 192.168.117.0/24
- 192.168.118.0/24
- 192.168.119.0/24
○ A. 192.168.110.0/20 ○ B. 192.168.110.0/21 ○ C. 192.168.110.0/22 ○ D. 192.168.112.0/20 ○ E. 192.168.112.0/21 ○ F. 192.168.112.0/22 Quick Answer: 175
Detailed Answer: 180
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Choose the most efficient summary address to encompass the following subnets:
- 172.16.4.0/24
- 172.16.5.0/24
- 172.16.6.0/24
- 172.16.128.0/24
○ A. 172.16.0.0/21 ○ B. 172.16.4.0/21 ○ C. 172.16.4.0/22 ○ D. 172.16.0.0/16 Quick Answer: 175
Detailed Answer: 181
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Is 172.20.2.255/23 a valid IP address?
○ A. No, it is the broadcast address for the 172.16.2.0/24 subnet. ○ B. No, it is the broadcast address for the 172.16.2.0/23 subnet. ○ C. Yes, but you cannot assign the IP address to a host. ○ D. Yes, and you can assign the IP address to a host. Quick Answer: 175
Detailed Answer: 181
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Given the subnet 10.5.12.0/22, which of the following IP addresses are valid host addresses residing within the network? (Choose three.)
○ A. 10.5.14.253 ○ B. 10.5.14.255 ○ C. 10.5.13.0 ○ D. 10.5.16.1 ○ E. 10.5.16.2 Quick Answer: 175
Detailed Answer: 181
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Which of the following is a valid equivalent of the IPv6 address 2001:0ab9:0000:0000:0003:0000:59ff:1ac5?
○ A. 2001:0ab9::3::59ff:1ac5 ○ B. 2001:ab9:0:0:3::59ff:1ac5 ○ C. 2001:ab9::359ff:1ac5 ○ D. 2001:0ab9:__:3:_:59ff:1ac5 Quick Answer: 175
Detailed Answer: 181
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Your organization has decided to move forward with a complete readdressing of the entire network. Using Figure 8.9 as a guide, break the 172.18.0.0/16 network into initial allocations for the regions. Draw lines connecting the correct allocations to the regions.
Figure 8.9 Network diagram.
Quick Answer: 175
Detailed Answer: 182
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Observe the following output from the show run command:
Current configuration : 104 bytes ! interface FastEthernet0/0 ip address 172.30.2.1 255.255.252.0 no ip route-cache no ip mroute-cache end
How many host IP addresses are able to be used from the network to which this FastEthernet interface is connected?
○ A. 255 ○ B. 1022 ○ C. 1024 ○ D. 2046 ○ E. 2048 Quick Answer: 175
Detailed Answer: 182
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Which of the following commands enables the IPv6 protocol on a router?
○ A. Router(config)#ipv6 unicast-routing ○ B. Router(config)#ipv6 enable ○ C. Router(config)#enable ipv6 ○ D. Router(config)#ipv6 ○ E. Router(config)#router ipv6 Quick Answer: 175
Detailed Answer: 182
Quick Check Answer Key
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C
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D
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C, F
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C, E
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A, B, D
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E
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E, I
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D
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A, C, D
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B, D, F
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C
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B
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B, C
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B, C, E
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A
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D
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E
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C
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F
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B
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B, D, F, H
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E
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D
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B
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A