CompTIA Network+ Practice Test (N10-009)

WPA3 is the recommended protocol and standard as it provides advanced security measures, including individualized data encryption and improved protection against brute-force attacks, which are crucial for protecting modern wireless networks.

To establish reverse DNS lookups for an IP address, a PTR record is needed in the DNS configuration. This record maps the IP address of a device or server to its canonical hostname, confirming the server's identity to other systems, specifically for functions like email delivery authentication. Other records like NS or MX do not perform this association for reverse lookups. NS records delegate DNS zones to other servers while MX records direct email to mail servers according to their priorities and are unrelated to reverse DNS configurations.

A rogue DHCP server can issue incorrect or malicious network settings to clients, directing traffic to unauthorized locations which potentially allows for man-in-the-middle attacks or data exfiltration. It disrupts network operations by allocating incorrect IP addresses and gateway information, posing significant security and operational risks. The other options, while potentially part of various attack strategies or network configurations, do not directly represent the typical outcomes of a rogue DHCP server.

Biometric locks are the most effective option listed for controlling physical access to a sensitive area like a data center. They require unique physical characteristics (e.g., fingerprints or retinal patterns), which are harder to duplicate or share compared to key cards or pin codes. Traditional key locks are less secure as keys can be copied or stolen. Pin code access systems can also be compromised if the code is shared or observed by unauthorized persons. While surveillance cameras are useful, they do not prevent entry but rather record it, making them less effective as the primary security measure.

VXLAN is primarily used for Layer 2 network isolation over a Layer 3 network, allowing for the creation of a large number of isolated Layer 2 networks across geographically dispersed data centers. This technology is essential in scenarios where you need to extend the same Layer 2 domain across different data centers without physical connectivity limitations. Choice 'Extending Layer 2 domains across multiple data centers' directly reflects the capability of VXLAN to extend network segments over a Layer 3 infrastructure, which is crucial for large and distributed network architectures. Other options, while feasible in certain contexts, do not specifically leverage the unique Layer 2 encapsulation capabilities of VXLAN.

Checking the current bandwidth usage and availability is the correct first step because increased latency during peak hours often indicates that bandwidth is being saturated. By understanding the usage patterns and identifying any bandwidth-hungry applications, a technician can take steps to manage the load or potentially increase bandwidth to reduce congestion, thus decreasing latency. Configuring Quality of Service for prioritization might be necessary if the bandwidth is not sufficient, but first, the usage needs to be assessed. Upgrading firmware or inspecting the physical layer might not directly relate to solving a congestion-induced latency issue during peak hours without first confirming the root cause is due to bandwidth issues.

The IP addresses 10.0.0.1, 172.16.254.3, and 192.168.1.1 are all classified as private IP addresses under RFC 1918, which reserves them for internal network use. Conversely, the address 8.8.4.4 is not part of any reserved private range and is routable on the global internet, making it a public IP address.

IPsec (Internet Protocol Security) is the correct answer because it is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec includes protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session. IPsec can be used to create a secure tunnel for transmitting data between two locations over the public Internet, providing both encapsulation and encryption, crucial for protecting data in transit. GRE, while capable of encapsulation, does not provide encryption inherently, making it less suitable for scenarios demanding high security. RIP and BGP are routing protocols and do not provide tunneling or encryption functionalities.

Dual stack is the correct choice as it allows devices to run IPv4 and IPv6 simultaneously, providing seamless communication compatibility with both protocols. Dual stack avoids the complexities and performance hits associated with translating between IPv4 and IPv6, aligning directly with the needs specified in the question. Tunneling, although a valid approach for supporting IPv4 and IPv6, involves encapsulating IPv6 packets within IPv4 packets (or vice versa), which can introduce additional overhead and complexity. NAT64, on the other hand, translates IPv6 addresses into IPv4 addresses, which is not required in scenarios where systems support both protocols natively as is the case in dual stack configurations.

TCP is the correct answer because it provides features such as sequencing and acknowledgment, error detection and recovery, and flow control mechanisms. These features ensure that data packets are delivered in order and without errors. UDP, while faster due to non-existent overhead for connection setup and error handling, does not guarantee packet delivery or order, making it inappropriate for scenarios requiring reliable data transmission. ICMP, primarily used for diagnostic or control purposes, is not suitable for data transfer.

RFC 1918 designates three private IPv4 blocks: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Only addresses inside these ranges are intended for internal networks and are filtered by Internet routers. 192.168.1.1 sits inside 192.168.0.0/16, so it is private. The other options (172.34.0.5, 203.0.113.10, 8.8.8.8) lie outside the private ranges and are publicly routable (203.0.113.0/24 and 198.51.100.0/24 are documentation ranges but still public).

Configuring a switch port speed to 100 Mbps on a connection where the connected devices support gigabit speeds will lead to a significant bottleneck. The port will limit the transmission speed to 100 Mbps, thereby underutilizing the gigabit capability of the connected devices and potentially causing network congestion due to slower data transfer rates. This misconfiguration does not directly involve protocol compatibility or increase noise levels, and it also won't necessarily result in complete data loss unless other factors are at play.

An extended ACL entry must include the protocol keyword followed by the source and destination networks with their wildcard masks. The line "permit ip 10.10.10.0 0.0.0.255 192.168.5.0 0.0.0.255" allows any IP traffic originating from the 10.10.10.0/24 subnet to reach any host on the 192.168.5.0/24 subnet. Because an implicit "deny ip any any" follows the ACL, all other source networks are automatically blocked from reaching the server subnet. The other options either reverse the source and destination fields, permit all sources, or fail to limit the destination network, so they do not meet the requirement.

NAT64 is the correct choice for transitioning from IPv4 to IPv6 by translating IPv6 addresses to IPv4 addresses and vice versa, allowing IPv4 clients to access IPv6 services transparently. Dual-stack architecture implies running both IPv4 and IPv6 on every device, which changes the set-up on clients. A Tunnel broker mainly creates a tunnel for IPv6 traffic over an IPv4 network, rather than facilitating communication between IPv4 clients and IPv6 services. DHCP relay is used to forward DHCP messages between clients and servers on different networks, but does not translate between IP versions.

Applying QoS policies to prioritize traffic ensures that critical applications, such as video conferencing, are given the required bandwidth even during high traffic periods. This is crucial for maintaining the quality and reliability of the video conferencing, which may be sensitive to bandwidth fluctuations. On the other hand, increasing bandwidth would not prioritize the specific needs of various types of traffic, traffic shaping alone might delay some packets to reduce burstiness without ensuring bandwidth availability, and traffic policing would limit the rate of traffic, potentially dropping packets when the bandwidth cap is exceeded.