CompTIA N10-009 Online Practice Questions and Exam Preparation

CompTIA N10-009 Online Questions & Answers

• Question 191:

  A network technician is working on a PC with a faulty NIC. The host is connected to a switch with secured ports. After testing the connection cables and using a known-good NIC, the host is still unable to connect to the network.

  Which of the following is causing the connection issue?

  A. MAC address of the new card
  B. BPDU guard settings
  C. Link aggregation settings
  D. PoE power budget
  A. MAC address of the new card

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  Explanation

  If a switch has port security enabled (such as sticky MAC or a configured allowed MAC), the port will only allow the original NIC's MAC address. When a new NIC with a different MAC address is installed, the port rejects traffic, preventing network connectivity.

  Option B: BPDU guard protects against rogue switches, not end hosts.

  Option C: Link aggregation applies when bundling multiple uplinks, not a single PC connection.

  Option D: PoE budget applies to powered devices like APs, not PCs.

  References:

  Domain: Network Troubleshooting -- Port security, MAC address filtering, switch security features.

• Question 192:

  A network engineer is completing a wireless installation in a new building. A requirement is that all clients be able to automatically connect to the fastest supported network.

  Which of the following best supports this requirement?

  A. Enabling band steering
  B. Disabling the 5GHz SSID
  C. Adding a captive portal
  D. Configuring MAC filtering
  A. Enabling band steering

• Question 193:

  Which of the following dynamic routing protocols is used on the internet?

  A. EIGRP
  B. BGP
  C. RIP
  D. OSPF
  B. BGP

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  Explanation

  BGP (Border Gateway Protocol)is the only dynamic routing protocol used across the internet. It's classified as an Exterior Gateway Protocol (EGP), responsible for routing between different autonomous systems (ASes).

  Option

  A. EIGRPand

  D. OSPF are Interior Gateway Protocols (IGPs), used within organizations.

  Option C. RIPis an outdated IGP with limited use, unsuitable for internet-scale routing.

  References:

  CompTIA Network+ N10-009 Official Objectives: 3.1-Compare and contrast various routing technologies.

• Question 194:

  A customer connects a firewall to an ISP router that translates traffic destined for the internet. The customer can connect to the internet but not to the remote site.

  Which of the following will verify the status of NAT?

  A. tcpdump
  B. nmap
  C. ipconfig
  D. tracert
  A. tcpdump

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  Explanation

  tcpdump is a command-line tool that can capture and analyze network traffic on a given interface. tcpdump can verify the status of NAT by showing the source and destination IP addresses of the packets before and after they pass through the ISP router that translates traffic destined for the internet. tcpdump can also show the NAT protocol and port numbers used by the router. nmap, ipconfig, and tracert are not suitable tools for verifying the status of NAT, as they do not show the IP address translation process.

• Question 195:

  A network engineer is troubleshooting connectivity for a newly installed server on an existing VLAN.

  The engineer reviews the following output:

  C:\> ipconfig

  IP Address: 192.168.100.225

  Mask: 255.255.255.224

  Gateway: 192.168.100.254

  Router# show ip route

  C 192.168.100.0/24 is directly connected, GigabitEthernet0/0

  Which of the following describes the issue?

  A. The server has an incorrect subnet mask
  B. There is a duplicate IP address on the network
  C. The DHCP address pool is exhausted
  D. The router is missing a default route
  A. The server has an incorrect subnet mask

  ---

  Explanation

  The server's subnet mask is 255.255.255.224 (/27), which covers IPs from 192.168.100.224 to 192.168.100.255. However, the router only recognizes 192.168.100.0/24, indicating a mismatch between the server's subnet and the router's

  network.

  Correct maskfor the /24 network is 255.255.255.0, allowing 256 IPs from 192.168.100.0 to 192.168.100.255.

  This mismatch would result in routing issues, especially with the gateway outside of the subnet range.

  References:

  CompTIA Network+ N10-009 Official Objectives: 5.2-Given a scenario, troubleshoot common wired connectivity issues.

• Question 196:

  A network engineer is implementing a new connection between core switches. The engineer deploys the following configurations:

  Core-SW01

  vlan 100

  name

  interface Ethernet1/1

  channel-group 1 mode active

  interface Ethernet1/2

  channel-group 1 mode active

  interface port-channel1

  switchport mode trunk

  switchport trunk allowed vlan 100

  Core-SW02

  vlan 100

  name

  interface Ethernet1/1

  switchport mode trunk

  switchport trunk allowed vlan 100

  interface Ethernet1/2

  switchport mode trunk

  switchport trunk allowed vlan 100

  interface port-channel1

  switchport mode trunk

  switchport trunk allowed vlan 100

  Which of the following is the state of the Core-SW01 port-channel interfaces?

  A. Incrementing CRC errors
  B. Error disabled
  C. Administratively down
  D. Suspended
  D. Suspended

  ---

  Explanation

  On Core-SW01, the ports are configured with LACP (mode active) for link aggregation. On Core-SW02, the ports are configured as independent trunks, not as part of an LACP group. Because of this mismatch, LACP cannot form the bundle, and the aggregated ports on SW01 will go into a suspended state.

  Option A: CRC errors suggest cabling or signal integrity issues, not configuration mismatches.

  Option B: Error disabled occurs when a violation (like BPDU Guard or port security) disables the port, not LACP mismatches.

  Option C: Administratively down indicates a shutdown command, which is not the case here.

  References:

  Domain: Network Troubleshooting - Port-channel/LACP configuration issues, interface states.

• Question 197:

  A technician needs to verify connectivity between two devices.

  Which of the following tools should be used first?

  A. ping
  B. traceroute
  C. netstat
  D. nslookup
  A. ping

  ---

  Explanation

  The ping command is a basic network troubleshooting tool used to test connectivity between two devices. It sends ICMP echo requests and waits for replies to determine whether the destination is reachable. It is typically the first step in troubleshooting because it quickly verifies Layer 3 connectivity. Traceroute is used to identify the path packets take, netstat displays connection statistics, and nslookup resolves DNS names. Ping provides a simple and immediate indication of connectivity status.

• Question 198:

  An organization recently connected a new computer to the LAN. The user is unable to ping the default gateway. The technician examines the configuration and sees a self-assigned IP address.

  Which of the following is the most likely cause?

  A. The DHCP server is not available
  B. An RFC1918 address is being used
  C. The TCP/IP stack is disabled
  D. A static IP is assigned
  A. The DHCP server is not available

  ---

  Explanation

  When a host fails to obtain an IP address from a DHCP server, it assigns itself an APIPA (Automatic Private IP Addressing) address in the 169.254.x.x range, commonly described as a "self-assigned IP." This prevents communication outside the local link, including reaching the default gateway.

  Option B: RFC1918 addresses are private ranges (10.x.x.x, 172.16?1.x.x, 192.168.x.x), but these are not self-assigned.

  Option C: If the TCP/IP stack were disabled, the host wouldn't have any IP at all.

  Option D: If a static IP were assigned, it would show a configured value, not self-assigned.

  References:

  Domain: Network Troubleshooting -- IP addressing issues, DHCP failures, APIPA behavior.

• Question 199:

  A Chief Executive Officer (CEO) of a company purchases a new phone that will be used while traveling to different countries. The CEO needs to be able to place outgoing calls and receive incoming calls on the phone using a SIM card.

  Which of the following cellular technologies does the CEO's phone need?

  A. WDMA
  B. CDMA
  C. GSM
  D. SLA
  C. GSM

  ---

  Explanation

  GSM (Global System for Mobile communications) is the international standard that uses SIM cards to authenticate and connect phones to the cellular network. GSM allows users to place and receive calls while traveling globally, provided they have a SIM card. CDMA, on the other hand, does not use SIM cards in the same way and is primarily used in the United States.

  References:

  CompTIA Network+ Study Guide, Chapter on Network Fundamentals)

• Question 200:

  Two companies need to securely connect their networks over the internet using a pre-shared key.

  Which technology should be used?

  A. SSL
  B. TLS
  C. IPSec VPN
  D. GRE
  C. IPSec VPN