CompTIA Updated N10-009 Exam Questions and Answers by malcolm

ESP (Encapsulating Security Payload) is an IPsec protocol that provides encryption, integrity, and authentication for data inside a VPN tunnel. It ensures that all tunneled traffic is encrypted.

B. SSH secures remote terminal sessions, not site-to-site VPN tunnels.

C. GRE (Generic Routing Encapsulation) provides encapsulation but does not encrypt data.

D. IKE (Internet Key Exchange) negotiates keys and establishes the IPsec tunnel but does not encrypt the payload itself.

References (CompTIA Network+ N10-009):

Domain: Network Security — VPN protocols, IPsec (AH vs. ESP), encryption in transit.

Comprehensive and Detailed Explanation (aligned to N10-009):

Multimode fiber uses multiple paths (modes) of light that bounce off the cladding to travel through the fiber. This is effective for shorter distances but more prone to dispersion.

A. Twinaxial is copper, not fiber.

B. Coaxial carries electrical signals, not light.

C. Single-mode fiber uses a single light path directly through the core without bouncing.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Fiber optics: single-mode vs. multimode.

To support 126 users, the subnet must provide at least 126 usable host addresses. In IPv4 subnetting, usable hosts are calculated as: (2^(host bits)) − 2, subtracting the network and broadcast addresses.

A /25 leaves 7 host bits (because 32 − 25 = 7). That yields 2^7 = 128 total addresses, and 128 − 2 = 126 usable—an exact fit and therefore the most efficient option listed.

A /24 provides 256 total addresses and 254 usable, which would waste more addresses than necessary. A /23 provides 512 total addresses and 510 usable—far more waste. A /26 leaves 6 host bits, giving 64 total addresses and 62 usable, which is not enough for 126 users.

The 10.2.2.0 address is within the private 10.0.0.0/8 range, so it’s appropriate for internal addressing. Therefore, 10.2.2.0/25 is the correct CIDR range for efficiently supporting 126 hosts.

The correct answer is PAT (Port Address Translation). According to the CompTIA Network+ N10-009 objectives, PAT is a form of Network Address Translation (NAT) that allows multiple internal hosts—or services—to be mapped to a single public IP address using different port numbers. PAT can also translate destination port numbers, which is exactly what is occurring in this scenario.

In this case, the firewall receives incoming traffic on port 80 (commonly used for HTTP) and forwards it to an internal server listening on port 88. This process is often referred to as port forwarding, which is a practical implementation of PAT. The firewall rewrites the destination port and potentially the destination IP address so that external clients can access internal services without exposing internal addressing schemes.

The other options do not apply. TLS and SSL are encryption protocols used to secure data in transit; they do not perform port translation. FHRP (First Hop Redundancy Protocol), such as HSRP or VRRP, provides gateway redundancy and high availability, not traffic forwarding or port remapping.

The Network+ objectives emphasize understanding how firewalls and NAT technologies manipulate IP addresses and ports to enable secure access to internal resources. PAT is the technology that enables this functionality, making it the correct answer.