CompTIA Security+ Question K-92

A system administrator attempts to ping a hostname and the response is 2001:4860:0:2001::68.
Which of the following replies has the administrator received?

A. The loopback address
B. The local MAC address
C. IPv4 address
D. IPv6 address

Answer: D

Explanation:
IPv6 addresses are 128-bits in length. 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 (:). The hexadecimal digits are case-insensitive, but IETF recommendations suggest the use of lower case letters. The full representation of eight 4-digit groups may be simplified by several techniques, eliminating parts of the representation.

CompTIA Security+ Question A-96

A security administrator must implement a network that is immune to ARP spoofing attacks. Which of the following should be implemented to ensure that a malicious insider will not be able to successfully use ARP spoofing techniques?

A. UDP
B. IPv6
C. IPSec
D. VPN

Answer: B

Explanation:
ARP is not used in IPv6 networks. The Address Resolution Protocol (ARP) is a telecommunication protocol used for resolution of network layer addresses into link layer addresses, a critical function in multiple-access networks. ARP is used for converting a network address (e.g. an IPv4 address) to a physical address like an Ethernet address (also named a MAC address). In Internet Protocol Version 6 (IPv6) networks, the functionality of ARP is provided by the Neighbor Discovery Protocol (NDP).

CompTIA Network+ Question C-97

Which of the following is an example of an IPv4 address?

A. 192:168:1:55
B. 192.168.1.254
C. 00:AB:FA:B1:07:34
D. ::1

Correct Answer: B

Explanation:
An IPv4 address is notated as four decimal numbers each between 0 and 255 separated by dots (xxx.xxx.xxx.xxx). Each number is known as an octet as it represents eight binary bits. All four octets make up a 32-bit binary IPv4 address.
In this question, 192.168.1.254 is a valid IPv4 address.

CompTIA Network+ Question B-49

A technician, Peter, has been tasked with assigning two IP addresses to WAN interfaces on connected routers. In order to conserve address space, which of the following subnet masks should Peter use for this subnet?

A. /24
B. /32
C. /28
D. /29
E. /30

Correct Answer: E

Explanation:
An IPv4 address consists of 32 bits. The first x number of bits in the address is the network address and the remaining bits are used for the host addresses. The subnet mask defines how many bits form the network address and from that, we can calculate how many bits are used for the host addresses.
In this question, the /30 subnet mask dictates that the first 30 bits of the IP address are used for network addressing and the remaining 2 bits are used for host addressing. The formula to calculate the number of hosts in a subnet is 2n – 2. The “n” in the host’s formula represents the number of bits used for host addressing. If we apply the formula (22 – 2), a /30 subnet mask will provide 2 IP addresses.

CompTIA Network+ Simulation 2

Corporate headquarters provided your office a portion of their class B subnet to use at a new office location. Allocate the minimum number of addresses (using CIDR notation) needed to accommodate each department.

Range Give: 172.30.232.0/24
Sales: 57 devices
HR: 23 devices
IT: 12 devices
Finance: 32 devices
Marketing: 9 devices

After accommodating each department, identify the unused portion of the subnet by responding to the question on the graphic. All drop downs must be filled. Instructions: When the simulation is complete, please select the Done button to submit.

All Networks have the range from /0 to/32

Correct Answer:


Explanation:
An IPv4 address consists of 32 bits. The first x number of bits in the address is the network address and the remaining bits are used for the host addresses. The subnet mask defines how many bits form the network address and from that, we can calculate how many bits are used for the host addresses.

The formula to calculate the number of hosts in a subnet is 2n – 2. The “n” in the host’s formula represents the number of bits used for host addressing. If we apply the formula (22 – 2), we can determine that the following subnets should be configured:

Sales network – /26 – This will provide up to 62 usable IP addresses (64-2 for subnet and broadcast IP) HR network – /27 – This will provide for up to 30 usable IP’s (32-2)
IT – /28 – This will provide for up to 14 usable IP’s (16-2)
Finance – /26 – Note that a /27 is 32 IP addresses but 2 of those are reserved for the network and broadcast IP’s and can’t be used for hosts. Marketing – /28
If we add up how many IP blocks are used that is 64+32+16+64+16=192. A /24 contains 256 IP addresses, so 256-192=64.
So the last unused box should be a /26, which equates to 64 addresses

CompTIA A+ Question K-46

Which of the following is the number of octets in an IPv4 address?

A. 4
B. 8
C. 16
D. 64

Correct Answer: A