15. What is the usable number of host IP addresses on a network that has a /26 mask?
a) 256
b) 254
c) 64
d) 62
e) 32
f) 16
Explanation: A /26 mask is the same as 255.255.255.192. The mask leaves 6 host bits. With 6 host bits, 64 IP addresses are possible. One address represents the subnet number and one address represents the broadcast address, which means that 62 addresses can then be used to assign to network devices.

16. Which address prefix range is reserved for IPv4 multicast?
a) 240.0.0.0 – 254.255.255.255
b) 224.0.0.0 – 239.255.255.255
c) 169.254.0.0 – 169.254.255.255
d) 127.0.0.0 – 127.255.255.255
Explanation: Multicast IPv4 addresses use the reserved class D address range of 224.0.0.0 to 239.255.255.255.

17. Refer to the exhibit. Match the network with the correct IP address and prefix that will satisfy the usable host addressing requirements for each network.
Explanation: Network A needs to use 192.168.0.128 /25, which yields 128 host addresses. Network B needs to use 192.168.0.0 /26, which yields 64 host addresses. Network C needs to use 192.168.0.96 /27, which yields 32 host addresses. Network D needs to use 192.168.0.80/30, which yields 4 host addresses.

18. A high school in New York (school A) is using videoconferencing technology to establish student interactions with another high school (school B) in Russia. The videoconferencing is conducted between two end devices through the Internet. The network administrator of school A configures the end device with the IP address 209.165.201.10. The administrator sends a request for the IP address for the end device in school B and the response is 192.168.25.10. Neither school is using a VPN. The administrator knows immediately that this IP will not work. Why?
Explanation: The IP address 192.168.25.10 is a private IP address, and it cannot be routed over the public Internet. It is likely that school B is using private addressing within its own network, and the administrator cannot establish a direct connection over the Internet with this private IP address.

19. Which three addresses are valid public addresses? (Choose three.)
a) 198.133.219.17
b) 128.107.12.117
c) 64.104.78.227
Explanation: Public IP addresses are routable on the Internet. Addresses like 198.133.219.17, 128.107.12.117, and 64.104.78.227 are all examples of public IP addresses.

20. A message is sent to all hosts on a remote network. Which type of message is it?
a) limited broadcast
b) multicast
c) directed broadcast
Explanation: A message sent to all hosts on a specific network is known as a directed broadcast. It is used to communicate with all hosts on a particular subnet.

21. A company has a network address of 192.168.1.64 with a subnet mask of 255.255.255.192. The company wants to create two subnetworks that would contain 10 hosts and 18 hosts respectively. Which two networks would achieve that? (Choose two.)
a) 192.168.1.16/28
b) 192.168.1.64/27
c) 192.168.1.128/27
d) 192.168.1.96/28
192.168.1.192/28
Explanation: Subnet 192.168.1.64 /27 has 5 bits that are allocated for host addresses and therefore will be able to support 32 addresses, but only 30 valid host IP addresses. Subnet 192.168.1.96/28 has 4 bits for host addresses and will be able to support 16 addresses, but only 14 valid host IP addresses.

22. Which address is a valid IPv6 link-local unicast address?
FEC8:1::FFFF
FD80::1:1234
FE80::1:4545:6578:ABC1
FE0A::100:7788:998F
FC90:5678:4251:FFFF
Explanation: IPv6 LLAs are in the fe80::/10 range. The /10 indicates that the first 10 bits are 1111 1110 10xx xxxx. The first hextet has a range of 1111 1110 1000 0000 (fe80) to 1111 1110 1011 1111 (febf).

23. Which of these addresses is the shortest abbreviation for the IP address: 3FFE:1044:0000:0000:00AB:0000:0000:0057?
3FFE:1044::AB::57
3FFE:1044::00AB::0057
3FFE:1044:0:0:AB::57
3FFE:1044:0:0:00AB::0057
3FFE:1044:0000:0000:00AB::57
3FFE:1044:0000:0000:00AB::0057
Explanation: The rules for reducing the notation of IPv6 addresses are: 1. Omit any leading 0s (zeros) in any hextet. 2. Replace any single, contiguous string of one or more 16-bit hextets consisting of all zeros with a double colon (::). 3. The double colon (::) can only be used once within an address.

24. A network administrator has received the IPv6 prefix 2001:DB8::/48 for subnetting. Assuming the administrator does not subnet into the interface ID portion of the address space, how many subnets can the administrator create from the /48 prefix?
16
256
4096
65536
Explanation: With a network prefix of 48, there will be 16 bits available for subnetting because the interface ID starts at bit 64. Sixteen bits will yield 65536 subnets.

25. Given IPv6 address prefix 2001:db8::/48, what will be the last subnet that is created if the subnet prefix is changed to /52?
2001:db8:0:f00::/52
2001:db8:0:8000::/52
2001:db8:0:f::/52
2001:db8:0:f000::/52
Explanation: Prefix 2001:db8::/48 has 48 network bits. If we subnet to a /52, we are moving the network boundary four bits to the right and creating 16 subnets. The first subnet is 2001:db8::/52 the last subnet is 2001:db8:0:f000::/52.

26. Consider the following range of addresses:
2001:0DB8:BC15:00A0:0000::
2001:0DB8:BC15:00A1:0000::
2001:0DB8:BC15:00A2:0000::
…
2001:0DB8:BC15:00AF:0000::

The prefix-length for the range of addresses is /60.
Explanation: All the addresses have the part 2001:0DB8:BC15:00A in common. Each number or letter in the address represents 4 bits, so the prefix-length is /60.

27. What type of IPv6 address is FE80::1?
loopback
link-local
multicast
global unicast
Explanation: Link-local IPv6 addresses start with FE80::/10, which is any address from FE80:: to FEBF::. Link-local addresses are used extensively in IPv6 and allow directly connected devices to communicate with each other on the link they share.

28. Refer to the exhibit. A company is deploying an IPv6 addressing scheme for its network. The company design document indicates that the subnet portion of the IPv6 addresses is used for the new hierarchical network design, with the site subsection to represent multiple geographical sites of the company, the sub-site section to represent multiple campuses at each site, and the subnet section to indicate each network segment separated by routers. With such a scheme, what is the maximum number of subnets achieved per sub-site?
16
256
4096
65536
Explanation: Because only one hexadecimal character is used to represent the subnet, that one character can represent 16 different values 0 through F.

29. What is used in the EUI-64 process to create an IPv6 interface ID on an IPv6 enabled interface?
the MAC address of the IPv6 enabled interface
a randomly generated 64-bit hexadecimal address
an IPv6 address that is provided by a DHCPv6 server
an IPv4 address that is configured on the interface
Explanation: The EUI-64 process uses the MAC address of an interface to construct an interface ID (IID). Because the MAC address is only 48 bits in length, 16 additional bits (FF:FE) must be added to the MAC address to create the full 64-bit interface ID.

30. What is the prefix for the host address 2001:DB8:BC15:A:12AB::1/64?
2001:DB8:BC15
2001:DB8:BC15:A
2001:DB8:BC15:A:1
2001:DB8:BC15:A:12
Explanation: The network portion, or prefix, of an IPv6 address is identified through the prefix length. A /64 prefix length indicates that the first 64 bits of the IPv6 address is the network portion. Hence the prefix is 2001:DB8:BC15:A.

31. An IPv6 enabled device sends a data packet with the destination address of FF02::1. What is the target of this packet?
the one IPv6 device on the link that has been uniquely configured with this address
all IPv6 enabled devices on the local link​ or network
only IPv6 DHCP servers
only IPv6 configured routers
Explanation: This address is one of the assigned IPv6 multicast addresses. Packets addressed to FF02::1 are for all IPv6 enabled devices on the link or network. FF02::2 is for all IPv6 routers that exist on the network.

32. Match the IPv6 address with the IPv6 address type. (Not all options are used.)
FF02::1:FFAE:F85F
2001:DB8::BAF:3F57:FE94
FF02::1
::1
Explanation: FF02::1:FFAE:F85F is a solicited node multicast address.
2001:DB8::BAF:3F57:FE94 is a global unicast address.
FF02::1 is the all node multicast address. Packets sent to this address will be received by all IPv6 hosts on the local link.
::1 is the IPv6 loopback address.
There are no examples of link local or unique local addresses provided.

33. Which IPv6 prefix is reserved for communication between devices on the same link?
FC00::/7
2001::/32
FE80::/10
FDFF::/7
Explanation: IPv6 link-local unicast addresses are in the FE80::/10 prefix range and are not routable. They are used only for communications between devices on the same link.

34. Which type of IPv6 address refers to any unicast address that is assigned to multiple hosts?
unique local
global unicast
link-local
anycast
Explanation: The IPv6 specifications include anycast addresses. An anycast address is any unicast IPv6 address that is assigned to multiple devices.

35. What are two types of IPv6 unicast addresses? (Choose two.)
multicast
loopback
link-local
anycast
broadcast
Explanation: Multicast, anycast, and unicast are types of IPv6 addresses. There is no broadcast address in IPv6. Loopback and link-local are specific types of unicast addresses.

36. Which service provides dynamic global IPv6 addressing to end devices without using a server that keeps a record of available IPv6 addresses?
stateful DHCPv6
SLAAC
static IPv6 addressing
stateless DHCPv6
Explanation: Using stateless address autoconfiguration (SLAAC), a PC can solicit a router and receive the prefix length of the network. From this information, the PC can then create its own IPv6 global unicast address.

37. Which protocol supports Stateless Address Autoconfiguration (SLAAC) for dynamic assignment of IPv6 addresses to a host?
ARPv6
DHCPv6
ICMPv6
UDP
Explanation: SLAAC uses ICMPv6 messages when dynamically assigning an IPv6 address to a host. DHCPv6 is an alternate method of assigning an IPv6 address to a host. ARPv6 does not exist. Neighbor Discovery Protocol (NDP) provides the functionality of ARP for IPv6 networks. UDP is the transport layer protocol used by DHCPv6.

38. Three methods allow IPv6 and IPv4 to co-exist. Match each method with its description. (Not all options are used.)
Explanation: Answers are not provided in the question.

39. A technician uses the ping 127.0.0.1 command. What is the technician testing?
the TCP/IP stack on a network host
connectivity between two adjacent Cisco devices
connectivity between a PC and the default gateway
connectivity between two PCs on the same network
physical connectivity of a particular PC and the network
Explanation: The ping 127.0.0.1 command is used to test the TCP/IP stack on a network host. The loopback address 127.0.0.1 is used to verify that the TCP/IP protocol stack is functioning correctly on the local device.

40. Refer to the exhibit. An administrator is trying to troubleshoot connectivity between PC1 and PC2 and uses the tracert command from PC1 to do it. Based on the displayed output, where should the administrator begin troubleshooting?
PC2
R1
SW2
R2
SW1
Explanation: The traceroute command shows the path a packet takes to reach its destination. In this case, the packet reaches the destination (PC2) in 1 hop, indicating that there's likely no issue with PC2 or its immediate connectivity. Therefore, the administrator should begin troubleshooting either on PC1 or further down the network path, starting from R1.

41. Which protocol is used by the traceroute command to send and receive echo-requests and echo-replies?
SNMP
ICMP
Telnet
TCP
Explanation: Traceroute uses the ICMP (Internet Control Message Protocol) to send and receive echo-request and echo-reply messages.

42. Which ICMPv6 message is sent when the IPv6 hop limit field of a packet is decremented to zero and the packet cannot be forwarded?
network unreachable
time exceeded
protocol unreachable
port unreachable
Explanation: ICMPv6 uses the hop limit field in the IPv6 packet header to determine if the packet has expired. If the hop limit field has reached zero, a router will send a time exceeded message back towards the source indicating that the router cannot forward the packet.

43. A user executes a traceroute over IPv6. At what point would a router in the path to the destination device drop the packet?
when the value of the Hop Limit field reaches 255
when the value of the Hop Limit field reaches zero
when the router receives an ICMP time exceeded message
when the target host responds with an ICMP echo reply message
Explanation: When a traceroute is performed, the value in the Hop Limit field of an IPv6 packet determines how many router hops the packet can travel. Once the Hop Limit field reaches a value of zero, it can no longer be forwarded, and the receiving router will drop the packet.

44. What is the purpose of ICMP messages?
to inform routers about network topology changes
to ensure the delivery of an IP packet
to provide feedback of IP packet transmissions
to monitor the process of a domain name to IP address resolution
Explanation: The purpose of ICMP messages is to provide feedback about issues related to the processing of IP packets.

45. What source IP address does a router use by default when the traceroute command is issued?
the highest configured IP address on the router
a loopback IP address
the IP address of the outbound interface
the lowest configured IP address on the router
Explanation: When sending an echo request message, a router will use the IP address of the exit interface as the source IP address. This default behavior can be changed by using an extended ping and specifying a specific source IP address.

46. Match each description with an appropriate IP address. (Not all options are used.)
Explanation: Answers are not provided in the question.

47. A user issues a ping 192.135.250.103 command and receives a response that includes a code of 1. What does this code represent?
host unreachable
protocol unreachable
port unreachable
network unreachable
Explanation: A response code of 1 indicates a host unreachable error. This means that the destination host (192.135.250.103) cannot be reached from the source host.

48. Which subnet would include the address 192.168.1.96 as a usable host address?
192.168.1.64/26
192.168.1.32/27
192.168.1.32/28
192.168.1.64/29
Explanation: For the subnet of 192.168.1.64/26, there are 6 bits for host addresses, yielding 64 possible addresses. However, the first and last subnets are the network and broadcast addresses for this subnet. Therefore, the range of host addresses for this subnet is 192.168.1.65 to 192.168.1.126. The other subnets do not contain the address 192.168.1.96 as a valid host address.

49. Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.
Explanation: This question refers to a Packet Tracer activity and requires specific actions within the activity to answer.

50. A host is transmitting a broadcast. Which host or hosts will receive it?
AD
all hosts in the same subnet
a specially defined group of hosts
the closest neighbor on the same network
all hosts on the Internet
Explanation: A broadcast is delivered to every host that has an IP address within the same network.

51. A host is transmitting a unicast. Which host or hosts will receive it?
one specific host
a specially defined group of hosts
all hosts on the Internet
the closest neighbor on the same network

52. A user issues a ping 2001:db8:FACE:39::10 command and receives a response that includes a code of 3. What does this code represent?
address unreachable
network unreachable
host unreachable
protocol unreachable

53. A host is transmitting a multicast. Which host or hosts will receive it?
a specially defined group of hosts
the closest neighbor on the same network
one specific host
directly connected network devices

60. Which is the compressed format of the IPv6 address 2001:0db8:0000:0000:0000:a0b0:0008:0001?
AD
2001:db8::a0b0:8:1
2001:db8::ab8:1:0:1000
2001:db80:0:1::80:1

61. Which is the compressed format of the IPv6 address fe80:09ea:0000:2200:0000:0000:0fe0:0290?
fe80:9ea:0:2200::fe0:290
fe80:9:20::b000:290
fe80:9ea0::2020:0:bf:e0:9290
fe80:9ea0::2020::bf:e0:9290

62. Which is the compressed format of the IPv6 address 2002:0042:0010:c400:0000:0000:0000:0909?
2002:42:10:c400::909
200:420:110:c4b::910:0:90
2002:4200::25:1090:0:99
2002:42::25:1090:0:99

63. Which is the compressed format of the IPv6 address 2001:0db8:0000:0000:0ab8:0001:0000:1000?
2001:db8::ab8:1:0:1000
2001:db8::a0b0:8:1
2001:db8:1::ab8:0:1
2001:db8:0:1::8:1

64. Which is the compressed format of the IPv6 address 2002:0420:00c4:1008:0025:0190:0000:0990?
AD
2002:420:c4:1008:25:190::990
2002:42:10:c400::909
2002:4200::25:1090:0:99
2002:42::25:1090:0:99

65. Which is the compressed format of the IPv6 address 2001:0db8:0000:0000:0000:a0b0:0008:0001?
2001:db8::a0b0:8:1
2001:db8:1::ab8:0:1
2001:db8::ab8:1:0:1000
2001:db8:0:1::8:1

66. Which is the compressed format of the IPv6 address fe80:0000:0000:0000:0220:0b3f:f0e0:0029?
fe80::220:b3f:f0e0:29
fe80:9ea:0:2200::fe0:290
fe80:9ea0::2020:0:bf:e0:9290
fe80:9ea0::2020::bf:e0:9290

67. Which is the compressed format of the IPv6 address 2001:0db8:0000:0000:0000:a0b0:0008:0001?
2001:db8::a0b0:8:1
2001:db8::ab8:1:0:1000
2001:db80:0:1::80:1
2001:db8:0:1::8:1

68. Which is the compressed format of the IPv6 address 2002:0042:0010:c400:0000:0000:0000:0909?
AD
2002:42:10:c400::909
2002:4200::25:1090:0:99
2002:420:c4:1008:25:190::990
2002:42::25:1090:0:99

69. Which is the compressed format of the IPv6 address fe80:09ea:0000:2200:0000:0000:0fe0:0290?
fe80:9ea:0:2200::fe0:290
fe80:9ea0::2020:0:bf:e0:9290
fe80::220:b3f:f0e0:29
fe80::0220:0b3f:f0e0:0029
Explanation: The compressed format of the given IPv6 address is fe80:9ea:0:2200::fe0:290.

70. A user issues a ping 2001:db8:FACE:39::10 command and receives a response that includes a code of 2. What does this code represent?
beyond scope of the source address
communication with the destination administratively prohibited
address unreachable
no route to destination
Explanation: A code of 2 in a ping response represents communication with the destination administratively prohibited.

71. A user issues a ping 192.135.250.103 command and receives a response that includes a code of 1. What does this code represent?
host unreachable
beyond scope of the source address
address unreachable
communication with the destination administratively prohibited
Explanation: A code of 1 in a ping response represents host unreachable.

72. A user issues a ping fe80:65ab:dcc1::100 command and receives a response that includes a code of 3. What does this code represent?
address unreachable
communication with the destination administratively prohibited
beyond scope of the source address
no route to destination
Explanation: A code of 3 in a ping response represents beyond scope of the source address.

73. A user issues a ping 10.10.14.67 command and receives a response that includes a code of 0. What does this code represent?
network unreachable
protocol unreachable
port unreachable
host unreachable
Explanation: A code of 0 in a ping response represents network unreachable.

74. A user issues a ping fe80:65ab:dcc1::100 command and receives a response that includes a code of 4. What does this code represent?
port unreachable
host unreachable
protocol unreachable
network unreachable
Explanation: A code of 4 in a ping response represents host unreachable.

75. A user issues a ping 198.133.219.8 command and receives a response that includes a code of 0. What does this code represent?
network unreachable
protocol unreachable
port unreachable
host unreachable
Explanation: A code of 0 in a ping response represents network unreachable.

76. A user issues a ping 2001:db8:3040:114::88 command and receives a response that includes a code of 4. What does this code represent?
port unreachable
host unreachable
protocol unreachable
network unreachable
Explanation: A code of 4 in a ping response represents host unreachable.

77. A user issues a ping 2001:db8:FACE:39::10 command and receives a response that includes a code of 2. What does this code represent?
beyond scope of the source address
host unreachable
protocol unreachable
network unreachable
Explanation: A code of 2 in a ping response represents communication with the destination administratively prohibited.