Pass the CompTIA CompTIA Network+ N10-009 Questions and answers with CertsForce

Spanning Tree Protocol (STP) uses bridge priority values to determine the root bridge in a switched network topology. Correctly configuring bridge priority helps in maintaining a loop-free and efficient network. The document explains:

“Spanning Tree Protocol (STP) uses bridge priority values to determine which switch will be the root bridge, ensuring loop prevention and efficient path selection within the network.”

A misaligned parabolic antenna can cause a significant increase in input errors because the signal is not properly focused or directed towards the receiving antenna, resulting in poor reception and data corruption. The document confirms:

“Misalignment of parabolic microwave antennas can lead to weak or incorrect signal reception, causing an increase in input errors and connectivity issues on the link.”

An IP Helper (IP Helper Address) allows DHCP requests to pass through routers and reach a DHCP server on another network.

DHCP broadcasts are not forwarded across routers by default, so an IP Helper Address is needed to relay the request.

This is crucial for large networks where a single DHCP server serves multiple subnets.

Option B (Reservation): Ensures a specific IP address is assigned to a MAC address but does not relay DHCP across networks.

Option C (Exclusion): Prevents specific IP addresses from being assigned, but does not help with DHCP relay.

Option D (Scope): Defines the range of IP addresses available for DHCP clients but does not assist in cross-network communication.

? Reference: CompTIA Network+ (N10-009) Official Study Guide – Section: DHCP and IP Addressing

Understanding the 169.254.x.x Address:

An IPv4 address in the range of 169.254.x.x is an Automatic Private IP Addressing (APIPA) address, assigned when a DHCP server is unavailable.

DHCP Server Offline:

APIPA Assignment: When a device cannot obtain an IP address from a DHCP server, it assigns itself an APIPA address to enable local network communication. This allows communication with other devices on the same local subnet but not with external networks.

Resolution: Ensure the DHCP server is operational. Check for connectivity issues between the virtual machine and the DHCP server, and verify the DHCP server settings.

Comparison with Other Options:

The subnet mask is incorrect: The subnet mask 255.255.0.0 is appropriate for the 169.254.x.x range and does not prevent external access by itself.

The IP address is an RFC1918 private address: RFC1918 addresses are private IP ranges (10.x.x.x, 172.16.x.x-172.31.x.x, 192.168.x.x) but 169.254.x.x is not one of them.

The DNS server is unreachable: While this could affect name resolution, it would not prevent the assignment of a non-APIPA address or local network communication.

Troubleshooting Steps:

Verify the DHCP server’s status and connectivity.

Restart the DHCP service if necessary.

Renew the IP lease on the virtual machine using commands such as ipconfig /renew (Windows) or dhclient (Linux).

Port mirroring, also known as SPAN (Switched Port Analyzer), is used to send a copy of network packets seen on one switch port (or an entire VLAN) to another port where the IDS is connected. This allows the IDS to passively inspect network traffic without interfering with the actual traffic flow. Port mirroring is an essential feature for implementing IDS in a network for traffic analysis and security monitoring.References: CompTIA Network+ study materials.

A cold site is a backup facility that provides infrastructure (such as power, cooling, and space) but does not have active IT resources installed. When a disaster occurs, IT teams must bring in and configure all necessary hardware and software before services can resume. This process can take weeks or longer—which matches the scenario described.

•Why not the other options?

•Hot site (A) – A hot site is a fully operational backup facility with up-to-date data and pre-configured hardware, allowing almost instant failover (minutes to hours).

•Warm site (B) – A warm site has pre-installed hardware and some software/configurations, but it requires some setup before becoming fully operational (hours to a few days).

•Active-active approach (D) – This means that multiple sites run simultaneously with load balancing, ensuring no downtime in case of a failure.

UDP (User Datagram Protocol) is a connectionless protocol that does not provide built-in mechanisms for error detection, retransmission, or acknowledgments. If a UDP packet is lost in transit, the protocol itself does not handle retransmission. However, some applications using UDP (e.g., TFTP or custom streaming protocols) may implement their own mechanisms to detect packet loss and request retransmission if needed.

Why not A? The data link layer (Layer 2) handles frame-level errors within a single network segment, not end-to-end packet loss across networks.

Why not B? The IP TTL (Time to Live) field prevents routing loops by decrementing with each hop, but IP does not handle retransmission.

Why not C? UDP does not use acknowledgments, so the sender does not expect or receive them.

A CNAME (Canonical Name) record is used in DNS to alias one domain name to another. This means that newapplication.comptia.org can be made to resolve to the same IP address as www.comptia.org by creating a CNAME record pointing newapplication.comptia.org to www.comptia.org. SOA (Start of Authority) is used for DNS zone information, MX (Mail Exchange) is for mail server records, and NS (Name Server) is for specifying authoritative DNS servers.

VLAN hopping is an attack where an attacker crafts packets with multiple VLAN tags, allowing them to traverse VLAN boundaries improperly. This can result in gaining unauthorized access to network segments that are supposed to be isolated. The other options do not involve the use of multiple network tags. MAC flooding aims to overwhelm a switch’s MAC address table, DNS spoofing involves forging DNS responses, and ARP poisoning involves sending fake ARP messages.