N10-009 Exam Dumps - CompTIA Network+ Questions and Answers

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

Quality of Service (QoS) is crucial for real-time services like video conferencing. It prioritizes voice and video packets over less critical traffic (like file downloads), reducing latency, jitter, and packet loss.

B. Network signal may apply to wireless, but it's not specific to video issues.

C. Time to live (TTL) affects packet lifespan, not performance or quality.

D. Load balancing manages traffic across multiple paths but doesn’t prioritize real-time traffic like QoS does.

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CompTIA Network+ N10-009 Official Objectives: 3.6 – Explain the characteristics of network topologies and types.

Microwaves are known to interfere with the 2.4GHz frequency, which is the same frequency used by many wireless networks. This can cause signal degradation and intermittent connectivity issues, especially if the WAP is placed near such devices.

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Border Gateway Protocol (BGP): BGP is the most commonly used routing protocol for interconnecting WANs, especially across the internet. It is used for exchanging routing information between autonomous systems (AS), making it the backbone protocol for large-scale WANs.

IGP (A): Interior Gateway Protocols like OSPF and EIGRP are typically used within a single AS, not between them.

EIGRP (B): While it is efficient, EIGRP is primarily used for intra-domain routing and not ideal for WAN interconnection.

OSPF (D): While OSPF can be used for WANs, it is not as common as BGP for inter-AS communication.

This process describes Zero-touch provisioning (ZTP), where a device automatically pulls its configuration from a cloud controller or URL once connected to the internet. It's common in SD-WAN and modern network appliances.

A. SASE (Secure Access Service Edge) refers to cloud-delivered network security, not a provisioning method.

C. Infrastructure as code automates infrastructure deployment using code, but this scenario specifically fits ZTP.

D. Configuration management tracks and maintains system configurations but doesn't describe the installation process.

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CompTIA Network+ N10-009 Official Objectives: 4.3 – Explain remote access methods and automation.

Understanding the Requirements

Network Address: 192.168.1.0/24

The /24 notation means a subnet mask of 255.255.255.0, providing 256 total addresses (192.168.1.0–192.168.1.255).

Usable hosts: 256 – 2 (network and broadcast) = 254.

Goal: Create 3 subnets, each with 30 hosts.

Each subnet needs enough addresses to accommodate 30 hosts, plus 2 reserved addresses (network and broadcast) per subnet.

Total addresses per subnet = 30 (hosts) + 2 (network/broadcast) = 32 addresses.

Subnetting Basics (Networking Fundamentals)

Subnet Mask: Determines how many bits are borrowed from the host portion to create subnets.

Original Mask: /24 (255.255.255.0) = 24 network bits, 8 host bits.

Formulae:

Number of subnets = 2^(number of borrowed bits).

Number of addresses per subnet = 2^(remaining host bits).

Usable hosts per subnet = 2^(remaining host bits) – 2.

We need:

At least 3 subnets.

At least 32 addresses per subnet (to fit 30 hosts + 2 reserved).

Step-by-Step Analysis

Determine Addresses Needed per Subnet:

32 addresses is a power of 2 (2^5 = 32).

This means each subnet requires 5 host bits (since 2^5 = 32 total addresses, and 32 – 2 = 30 usable hosts).

Calculate Remaining Bits:

Original network has 8 host bits (/24).

If 5 bits are left for hosts, we borrow: 8 – 5 = 3 bits for subnetting.

New Subnet Mask:

Original mask: /24 (24 network bits).

Borrow 3 bits: 24 + 3 = /27.

/27 = 255.255.255.224 (binary: 11111111.11111111.11111111.11100000).

Verify Requirements:

Number of Subnets: 2^3 = 8 subnets (meets the requirement of at least 3).

Addresses per Subnet: 2^5 = 32 addresses.

Usable Hosts per Subnet: 32 – 2 = 30 hosts (exactly meets the requirement).

Subnet Breakdown:

Increment: 256 – 224 = 32 (each subnet increments by 32 in the fourth octet).

Subnets:

192.168.1.0–192.168.1.31 (Network: .0, Broadcast: .31, Hosts: .1–.30)

192.168.1.32–192.168.1.63 (Network: .32, Broadcast: .63, Hosts: .33–.62)

192.168.1.64–192.168.1.95 (Network: .64, Broadcast: .95, Hosts: .65–.94)

(And 5 more subnets up to 192.168.1.255.)

Three subnets fit perfectly with 30 hosts each.

Evaluating the Options

A. 255.255.255.128 (/25):

Borrow 1 bit: 24 + 1 = /25.

Subnets: 2^1 = 2 (not enough, need 3).

Host bits: 7 (2^7 = 128 addresses, 126 hosts).

Why Not: Only 2 subnets, fails the requirement.

B. 255.255.255.192 (/26):

Borrow 2 bits: 24 + 2 = /26.

Subnets: 2^2 = 4 (meets 3).

Host bits: 6 (2^6 = 64 addresses, 62 hosts).

Why Not: 62 hosts exceeds 30, but it’s overkill; /27 is more efficient and still valid.

C. 255.255.255.224 (/27):

Borrow 3 bits: 24 + 3 = /27.

Subnets: 2^3 = 8 (meets 3).

Host bits: 5 (2^5 = 32 addresses, 30 hosts).

Why Yes: Perfectly fits 3 subnets with exactly 30 hosts each.

D. 255.255.255.240 (/28):

Borrow 4 bits: 24 + 4 = /28.

Subnets: 2^4 = 16 (meets 3).

Host bits: 4 (2^4 = 16 addresses, 14 hosts).

Why Not: Only 14 hosts per subnet, fails the 30-host requirement.

Why /27 (255.255.255.224) is Best

It provides exactly 30 usable hosts per subnet, avoiding waste while meeting the minimum requirement.

It allows 8 subnets, exceeding the need for 3, ensuring flexibility.

The study guide emphasizes efficient subnet design, and /27 balances host count and subnet availability.

CompTIA Network+ Context

Networking Fundamentals: Subnetting is a core skill, requiring understanding of CIDR, binary conversion, and address allocation.

Example from Study Guide: Similar problems calculate subnet masks for specific host counts, reinforcing /27 as a common solution for ~30 hosts.

This describes a Spanning Tree Protocol (STP) loop. If STP isn’t correctly configured or a redundant link is added without STP protection, it causes broadcast storms and network outages.

A. Unused ports disabled would not affect the entire network.

B. Missing default gateway on a switch doesn’t cause total network loss.

**C. Connecting a switch to an access port can cause VLAN mismatches, but not total connectivity loss unless a loop forms.

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CompTIA Network+ N10-009 Official Objectives: 3.6 – Explain the characteristics of network topologies and types.

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A split-tunnel VPN allows a device to route some traffic through the VPN (typically corporate traffic) while sending other traffic (like general internet browsing) directly over the local internet connection. This reduces the load on the corporate network because not all traffic is routed through the VPN tunnel.

Site-to-site VPNs are for permanent links between locations.

Full-tunnel VPNs route all traffic through the VPN, increasing the bandwidth usage on the corporate network.

GRE (Generic Routing Encapsulation) is a tunneling protocol that doesn’t encrypt and doesn't reduce bandwidth usage by itself.

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CompTIA Network+ N10-009 Official Objectives: 3.3 – Given a scenario, configure and deploy common VPN technologies.

To provide a complete solution for configuring the access layer switches, let's proceed with the following steps:

Identify the correct VLANs for each device and port.

Enable necessary ports and disable unused ports.

Configure fault-tolerant connections between the switches.

Port 1 Configuration (Uplink to Core Switch)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN90, VLAN120, VLAN150, VLAN220

Port 2 Configuration (Uplink to Core Switch)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN90, VLAN120, VLAN150, VLAN220

Port 3 Configuration (Server Connection)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN90 (Servers)

Port 4 Configuration (Server Connection)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN90 (Servers)

Port 5 Configuration (Wired Users and WLAN)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN120, VLAN150

Port 6 Configuration (Wired Users and WLAN)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN120, VLAN150

Port 7 Configuration (Voice and Wired Users)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN90, VLAN120, VLAN220

Port 8 Configuration (Voice, Printers, and Wired Users)

Status: Enabled

LACP: Enabled

Speed: 1000

Duplex: Full

VLAN Configuration: Tagged for VLAN60, VLAN90, VLAN120, VLAN220

Port 1 Configuration (Unused)

Status: Disabled

LACP: Disabled

Port 2 Configuration (Unused)

Status: Disabled

LACP: Disabled

Port 3 Configuration (Connection to Device)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN1 (Default)

Port 4 Configuration (Connection to Device)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN1 (Default)

Port 5 Configuration (Connection to Device)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN1 (Default)

Port 6 Configuration (Connection to Device)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN1 (Default)

Port 7 Configuration (Connection to Device)

Status: Enabled

LACP: Disabled

Speed: 1000

Duplex: Full

VLAN Configuration: Untagged for VLAN1 (Default)

Ports 1 and 2 on Switch 1 are configured as trunk ports with VLAN tagging enabled for all necessary VLANs.

Ports 3 and 4 on Switch 1 are configured for server connections with VLAN 90 untagged.

Ports 5, 6, 7, and 8 on Switch 1 are configured for devices needing access to multiple VLANs.

Unused ports on Switch 3 are disabled.

Ports 3, 4, 5, 6, and 7 on Switch 3 are enabled for default VLAN1.

Core Switch Ports should be configured as needed for uplinks to Switch 1.

Ensure LACP is enabled for redundancy on trunk ports between switches.

By following these configurations, each device will access only its correctly associated network, unused switch ports will be disabled, and fault-tolerant connections will be established between the switches.