CISCO CCNA Exam – Q148

What will happen if a private IP address is assigned to a public interface connected to an ISP?

A. Addresses in a private range will not be routed on the Internet backbone.
B. Only the ISP router will have the capability to access the public network.
C. The NAT process will be used to translate this address to a valid IP address.
D. A conflict of IP addresses happens, because other public routers can use the same range.

Correct Answer: A

Explanation:
Private RFC 1918 IP addresses are meant to be used by organizations locally within their own network only, and cannot be used globally for Internet use.

CISCO CCNA Exam – Q147

Which two benefits are provided by using a hierarchical addressing network addressing scheme? (Choose two.)

A. reduces routing table entries
B. auto-negotiation of media rates
C. efficient utilization of MAC addresses
D. dedicated communications between devices
E. ease of management and troubleshooting

Correct Answers: A,E

Explanation:
Here are some of the benefits of hierarchical addressing:

Reduced number of routing table entries — whether it is with your Internet routers or your internal routers, you should try to keep your routing tables as small as possible by using route summarization. Route summarization is a way of having a single IP address represent a collection of IP addresses; this is most easily accomplished when you employ a hierarchical addressing plan. By summarizing routes, you can keep your routing table entries (on the routers that receive the summarized routes) manageable, which offers the following benefits:

  • More efficient routing
  • A reduced number of CPU cycles when recalculating a routing table or sorting through the routing table entries to find a match
  • Reduced router memory requirements
  • Reduced bandwidth required to send the fewer, smaller routing updates
  • Faster convergence after a change in the network
  • Easier troubleshooting
  • Increased network stability

Efficient allocation of addresses — Hierarchical addressing lets you take advantage of all possible addresses because you group them contiguously.

CISCO CCNA Exam – Q146

What is the alternative notation for the IPv6 address B514:82C3:0000:0000:0029:EC7A:0000:EC72?

A. B514 : 82C3 : 0029 : EC7A : EC72
B. B514 : 82C3 :: 0029 : EC7A : EC72
C. B514 : 82C3 : 0029 :: EC7A : 0000 : EC72
D. B514 : 82C3 :: 0029 : EC7A : 0 : EC72

Correct Answer: D

Explanation:
There are two ways that an IPv6 address can be additionally compressed: compressing leading zeros and substituting a group of consecutive zeros with a single double colon (::). Both of these can be used in any number of combinations to notate the same address. It is important to note that the double colon (::) can only be used once within a single IPv6 address notation. So, the extra 0’s can only be compressed once.

CISCO CCNA Exam – Q145

Refer to the diagram.

All hosts have connectivity with one another. Which statements describe the addressing scheme that is in use in the network? (Choose three.)

A. The subnet mask in use is 255.255.255.192.
B. The subnet mask in use is 255.255.255.128.
C. The IP address 172.16.1.25 can be assigned to hosts in VLAN1
D. The IP address 172.16.1.205 can be assigned to hosts in VLAN1
E. The LAN interface of the router is configured with one IP address.
F. The LAN interface of the router is configured with multiple IP addresses.

Correct Answers: B,C,F

Explanation:
The subnet mask in use is 255.255.255.128: This is subnet mask will support up to 126 hosts, which is needed.
The IP address 172.16.1.25 can be assigned to hosts in VLAN1: The usable host range in this subnet is 172.16.1.1-172.16.1.126
The LAN interface of the router is configured with multiple IP addresses: The router will need 2 subinterfaces for the single physical interface, one with an IP address that belongs in each VLAN.

CISCO CCNA Exam – Q144

Which two statements describe characteristics of IPv6 unicast addressing? (Choose two.)

A. Global addresses start with 2000::/3.
B. Link-local addresses start with FE00:/12.
C. Link-local addresses start with FF00::/10.
D. There is only one loopback address and it is ::1.
E. If a global address is assigned to an interface, then that is the only allowable address for the interface.

Correct Answers: A, D

Explanation:
Below is the list of common kinds of IPv6 addresses:
CISCO CCNA Exam – Q144

CISCO CCNA Exam – Q143

The network administrator has been asked to give reasons for moving from IPv4 to IPv6. What are two valid reasons for adopting IPv6 over IPv4? (Choose two.)

A. no broadcast
B. change of source address in the IPv6 header
C. change of destination address in the IPv6 header
D. Telnet access does not require a password
E. autoconfiguration
F. NAT

Correct Answers: A, E

Explanation:
IPv6 does not use broadcasts, and autoconfiguration is a feature of IPV6 that allows for hosts to automatically obtain an IPv6 address.

CISCO CCNA Exam – Q142

An administrator must assign static IP addresses to the servers in a network. For network 192.168.20.24/29, the router is assigned the first usable host address while the sales server is given the last usable host address. Which of the following should be entered into the IP properties box for the sales server?

A.
IP address: 192.168.20.14
Subnet Mask: 255.255.255.248
Default Gateway: 192.168.20.9
B.
IP address: 192.168.20.254
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.20.1
C.
IP address: 192.168.20.30
Subnet Mask: 255.255.255.248
Default Gateway: 192.168.20.25
D.
IP address: 192.168.20.30
Subnet Mask: 255.255.255.240
Default Gateway: 192.168.20.17
E.
IP address: 192.168.20.30
Subnet Mask: 255.255.255.240
Default Gateway: 192.168.20.25

Correct Answer: C

Explanation:
For the 192.168.20.24/29 network, the usable hosts are 192.168.24.25 (router) – 192.168.24.30 (used for the sales server).

CISCO CCNA Exam – Q141

Which subnet mask would be appropriate for a network address range to be subnetted for up to eight LANs, with each LAN containing 5 to 26 hosts?

A. 0.0.0.240
B. 255.255.255.252
C. 255.255.255.0
D. 255.255.255.224
E. 255.255.255.240

Correct Answer: D

Explanation:
For a class C network, a mask of 255.255.255.224 will allow for up to 8 networks with 32 IP addresses each (30 usable).

CISCO CCNA Exam – Q140

How many bits are contained in each field of an IPv6 address?

A. 24
B. 4
C. 8
D. 16

Correct Answer: D

Explanation:
An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). An example of an IPv6 address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

CISCO CCNA Exam – Q139

What are three approaches that are used when migrating from an IPv4 addressing scheme to an IPv6 scheme. (Choose three.)

A. enable dual-stack routing
B. configure IPv6 directly
C. configure IPv4 tunnels between IPv6 islands
D. use proxying and translation to translate IPv6 packets into IPv4 packets
E. statically map IPv4 addresses to IPv6 addresses
F. use DHCPv6 to map IPv4 addresses to IPv6 addresses

Correct Answer: A, C, D

Explanation:
Several methods are used terms of migration including tunneling, translators, and dual stack. Tunnels are used to carry one protocol inside another, while translators simply translate IPv6 packets into IPv4 packets. Dual stack uses a combination of both native IPv4 and IPv6. With dual stack, devices are able to run IPv4 and IPv6 together and if IPv6 communication is possible that is the preferred protocol. Hosts can simultaneously reach IPv4 and IPv6 content.