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.

CISCO CCNA Exam – Q138

Refer to the exhibit.
CISCO CCNA Exam – Q138

In this VLSM addressing scheme, what summary address would be sent from router A?

A. 172.16.0.0 /16
B. 172.16.0.0 /20
C. 172.16.0.0 /24
D. 172.32.0.0 /16
E. 172.32.0.0 /17
F. 172.64.0.0 /16

Correct Answer: A

Explanation:
Router A receives 3 subnets: 172.16.64.0/18, 172.16.32.0/24 and 172.16.128.0/18.
All these 3 subnets have the same form of 172.16.x.x so our summarized subnet must be also in that form.
The smallest subnet mask of these 3 subnets is /18 so our summarized subnet must also have its subnet mask equal or smaller than /18.
Only answer A has these 2 conditions .

CISCO CCNA Exam – Q137

How is an EUI-64 format interface ID created from a 48-bit MAC address?

A. by appending 0xFF to the MAC address
B. by prefixing the MAC address with 0xFFEE
C. by prefixing the MAC address with 0xFF and appending 0xFF to it
D. by inserting 0xFFFE between the upper three bytes and the lower three bytes of the MAC address
E. by prefixing the MAC address with 0xF and inserting 0xF after each of its first three bytes

Correct Answer: D

Explanation:
The modified EUI-64 format interface identifier is derived from the 48-bit link-layer (MAC) address by inserting the hexadecimal number FFFE between the upper three bytes (OUI field) and the lower three bytes (serial number) of the link layer address.

CISCO CCNA Exam – Q136

Refer to the exhibit.
CISCO CCNA Exam – Q136

What is the most efficient summarization that R1 can use to advertise its networks to R2?

A.
172.1.0.0/22
B.
172.1.0.0/21
C.
172.1.4.0/22
D.
172.1.4.0/24
172.1.5.0/24
172.1.6.0/24
172.1.7.0/24
E.
172.1.4.0/25
172.1.4.128/25
172.1.5.0/24
172.1.6.0/24
172.1.7.0/24

Correct Answer: C

Explanation:
The 172.1.4.0/22 subnet encompasses all routes from the IP range 172.1.4.0 – 172.1.7.255.

CISCO CCNA Exam – Q135

Which option is a valid IPv6 address?

A. 2001:0000:130F::099a::12a
B. 2002:7654:A1AD:61:81AF:CCC1
C. FEC0:ABCD:WXYZ:0067::2A4
D. 2004:1:25A4:886F::1

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. The leading 0’s in a group can be collapsed using ::, but this can only be done once in an IP address.

CISCO CCNA Exam – Q134

Which three are characteristics of an IPv6 anycast address? (Choose three.)

A. one-to-many communication model
B. one-to-nearest communication model
C. any-to-many communication model
D. a unique IPv6 address for each device in the group
E. the same address for multiple devices in the group
F. delivery of packets to the group interface that is closest to the sending device

Correct Answers: B, E, F

Explanation:
A new address type made specifically for IPv6 is called the Anycast Address. These IPv6 addresses are global addresses, these addresses can be assigned to more than one interface unlike an IPv6 unicast address. Anycast is designed to send a packet to the nearest interface that is a part of that anycast group.
The sender creates a packet and forwards the packet to the anycast address as the destination address which goes to the nearest router. The nearest router or interface is found by using the metric of a routing protocol currently running on the network. However in a LAN setting the nearest interface is found depending on the order the neighbors were learned. The anycast packet in a LAN setting forwards the packet to the neighbor it learned about first.