CompTIA Updated N10-008 Exam Questions and Answers by camilla

This subnet mask will allow you to have six usable IP addresses in each subnet, with a minimum of wasted addresses. You can use the following formula to calculate the number of subnets and the subnet ID for each subnet:

Number of subnets = 2^network bits Subnet ID = (subnet number - 1) x number of host addresses + network address

The network bits are the number of 1s in the binary representation of the subnet mask, and the network address is the first address in the range. For example, if your range is 192.168.1.0/27, then the network bits are 27, the network address is 192.168.1.0, and the number of host addresses is 30. Therefore, the number of subnets is 2^27, and the subnet ID for the first subnet is (1 - 1) x 30 + 192.168.1.0 = 192.168.1.0. The subnet ID for the second subnet is (2 - 1) x 30 + 192.168.1.0 = 192.168.1.32, and so on.

References

• Subnet masks are covered in Objective 1.4 of the CompTIA Network+ N10-008 certification exam1.
• Subnet masks can be calculated based on binary and CIDR-block notations2.
• Subnet masks can be used to determine the number of host bits and host addresses3.

1: CompTIA Network+ Certification Exam Objectives, page 4 2: IPv4 Subnet Masks – N10-008 CompTIA Network+ : 1.41 3: Calculating IPv4 Subnets and Hosts – N10-008 CompTIA Network+ : 1.44

 ARP spoofing is a technique that involves sending fake ARP messages to associate an attacker’s MAC address with an IP address of a legitimate device on the network. This allows the attacker to intercept, modify, or drop the traffic that is intended for the legitimate device. This is also known as an on-path attack, or a man-in-the-middle attack, because the attacker is positioned between two communicating parties and can alter or manipulate the data. ARP spoofing can be used for various malicious purposes, such as stealing sensitive information, hijacking sessions, redirecting traffic, or launching other attacks. DNS poisoning, DoS attack, and rogue access point are not directly related to ARP spoofing, although they can be used in conjunction with it or as a result of it. DNS poisoning is a technique that involves corrupting the DNS cache of a server or a client with false information, such as mapping a domain name to an IP address of an attacker’s server. This can be used to redirect users to malicious websites, phishing pages, or malware downloads. DoS attack is a technique that involves overwhelming a target system or network with excessive requests or traffic, such as SYN floods, ICMP floods, or UDP floods. This can be used to degrade the performance, availability, or functionality of the target system or network. Rogue access point is a wireless access point that is installed or configured without authorization on a network. This can be used to provide unauthorized access to the network, capture network traffic, or launch other attacks. References:

• ARP Spoofing
• On-path Attack
• DNS Poisoning
• [DoS Attack]
• [Rogue Access Point]
• [Network + N10-008 practice exam]
• [CompTIA N10-008 Free Certification Exam Material]

An A record, also known as an address record, is a type of DNS record that maps a hostname to an IPv4 address. An A record is used to resolve a domain name to an IP address, so that clients can connect to the server or service by using the domain name instead of the IP address. For example, an A record can map www.example.com to 192.0.2.1.

An A record is the most common type of DNS record for cloud DNS, as it allows the company to use a custom domain name for their cloud services, such as web hosting, email, or storage. An A record can also be used to create subdomains, such as blog.example.com or mail.example.com, that point to different IP addresses or servers.

The other options are not correct because they are not the best type of DNS record for cloud DNS. They are:

• MX. MX stands for mail exchange, and it is a type of DNS record that specifies the mail servers that are responsible for receiving and delivering email messages for a domain name. MX records are used for email services, but they are not sufficient for cloud DNS, as they do not map a hostname to an IP address.
• CNAME. CNAME stands for canonical name, and it is a type of DNS record that specifies an alias name for another domain name. CNAME records are used to create multiple names for the same IP address or server, such as www.example.com and example.com. CNAME records are useful for cloud DNS, but they are not the best type, as they depend on another A record to resolve the IP address.
• NS. NS stands for name server, and it is a type of DNS record that delegates a DNS zone to an authoritative server. NS records are used to specify which DNS servers are responsible for answering queries for a domain name or a subdomain. NS records are essential for cloud DNS, but they are not the best type, as they do not map a hostname to an IP address.

References1: DNS records overview | Google Cloud2: Network+ (Plus) Certification | CompTIA IT Certifications3: ClouDNS: What is a DNS record?

A biometric reader is a device that scans a person’s physical characteristics, such as fingerprints, iris, or face, and compares them to a database of authorized users. A biometric reader can be used to restrict access to a server room and prevent unauthorized entry. A biometric reader provides a high level of security and cannot be easily bypassed or duplicated.

References: Network+ Study Guide Objective 5.1: Summarize the importance of physical security controls.