CompTIA Network+ Question B-15

A company has changed ISPs for their office and ordered a new 250 Mbps symmetrical Internet connection. As a result, they have been given a new IP range. The ISP has assigned the company 10.10.150.16 /28. The company gateway router has the following interface configuration facing the ISP:
Interface A:
IP address: 10.10.150.16
Subnet mask: 255.255.255.240
Default gateway: 10.10.150.32
Speed: 1000 Mbps Duplex: Auto
State: No Shutdown

None of the workstations at the company are able to access the Internet. Which of the following are the reasons? (Select TWO).

A. There is a duplex mismatch between the router and ISP.
B. The router interface is turned off.
C. The interface is set to the incorrect speed.
D. The router is configured with the incorrect subnet mask.
E. The router interface is configured with the incorrect IP address.
F. The default gateway is configured incorrectly.

Correct Answer: EF

Explanation:
According to the IP Address Range Calculator, for the given subnet mask and the IP range address range assigned by the ISP, the first host address should be 10.10.150.17 and the broadcast address should be 10.10.150.31. Therefore, the router interface is configured with the incorrect IP address and the default gateway is configured incorrectly.

CompTIA Network+ Question B-12

A technician is trying to determine the IP address of a customer’s router. The customer has an IP address of 192.168.1.55/24. Which of the following is the address of the customer’s router?

A. 192.168.0.55
B. 192.168.1.0
C. 192.168.1.1
D. 192.168.5.5
E. 255.255.255.0

Correct Answer: C

CompTIA Network+ Question B-1

A network administrator is using a packet analyzer to determine an issue on the local LAN. Two separate computers are showing an error message on the screen and are unable to communicate with other computers in the same lab. The network administrator looks at the following output:

SRC MAC SRC IP DST MAC DST IP
00:1D:1F:AB:10:7D192.168.1.10:200015:BE:9F:AB:10:1D192.168.1.14:1200
05:DD:1F:AB:10:27192.168.1.10:100022:C7:2F:AB:10:A2192.168.1.15:1300

Given that all the computers in the lab are directly connected to the same switch, and are not using any virtualization technology, at which of the following layers of the OSI model is the problem occurring?

A. Network
B. Application
C. Data link
D. Transport

Correct Answer: A

Explanation:
If we look at the Source Mac column, we can see two different MAC addresses. Every network interface card has a unique MAC address. These are the network cards in the two separate computers.
If we look in the Source IP column, we can see that the two network cards have been assigned the same IP address (192.168.1.10). This is the problem in this question. The error message on the screens will be saying that “An IP conflict exists”. Every network card connected to the network needs to be configured with a different IP address.
As the problem is with the IP address configuration of the two computers, we know that the problem is occurring at the Network layer (layer 3) of the OSI model. The network layer is responsible for Internet Protocol (IP) addressing and routing.

CompTIA Network+ Question A-48

A technician is attempting to resolve an issue with users on the network not being able to access websites. The technician pings the default gateway and DNS servers successfully. Pinging a website by URL is unsuccessful but using a known IP address is successful. Which of the following will resolve the issue?

A. Update the HOST file with the URLs for all websites
B. Use NSLOOKUP to resolve URLs
C. Ensure ICMP messages can pass through the firewall
D. Enable port 53 on the firewall

Correct Answer: D

CompTIA Network+ Question A-45

When configuring a new server, a technician requests that an MX record be created in DNS for the new server, but the record was not entered properly. Which of the following was MOST likely installed that required an MX record to function properly?

A. Load balancer
B. FTP server
C. Firewall DMZ
D. Mail server

Correct Answer: D

Explanation:
A mail exchanger record (MX record) is a DNS record used by email servers to determine the name of the email server responsible for accepting email for the recipient’s domain.
For example a user sends an email to recipient@somedomain.com. The sending user’s email server will query the somedomain.com DNS zone for an MX record for the domain. The MX record will specify the hostname of the email server responsible for accepting email for the somedomain.com domain, for example, mailserver.somedomain.com. The sending email server will then perform a second DNS query to resolve mailserver.somedomain.com to an IP address. The sending mail server will then forward the email to the destination mail server.

CompTIA Network+ Question A-43

After connecting a workstation directly to a small business firewall, a network administrator is trying to manage it via HTTPS without losing its stored configuration. The only two pieces of information that the network administrator knows about the firewall are the management interface MAC address, which is 01:4a:d1:fa:b1:0e, and the administrator’s password. Which of the following will allow the administrator to log onto the firewall via HTTPS if the management’s IP address is unknown and the administrator’s workstation IP address is 192.168.0.10/23?

A. Use the reset button on the back of the firewall to restore it to its factory default, and then log onto
B. Run the following command on the administrator’s workstation: arp –s 192.168.1.200 01:4a:d1:fa:b1:0e
C. Use an SNMP tool to query the firewall properties and determine the correct management IP address
D. Use a crossover cable to connect to the console port and reconfigure the firewall management IP to 192.168.0.1

Correct Answer: B

Explanation:
Address Resolution Protocol (ARP) is used to resolve IP addresses to MAC addresses. The arp –s command adds a static permanent address to the ARP cache. This will allow the administrator to access the firewall.

CompTIA Network+ Question A-34

A network technician was tasked to install a network printer and share it to a group of five human resource employees. The technician plugged the device into a LAN jack, but was unable to obtain an IP address automatically. Which of the following is the cause of the problem?

A. DNS
B. Wrong TCP port
C. Split horizon
D. DHCP scope

Correct Answer: D

CompTIA Network+ Question A-32

A user is unable to connect to a server in another building. A technician is troubleshooting the issue and determines the following:
1) Client PC 1 has an IP address if 192.168.10.25/25
2) PC 1 can successfully ping its gateway of 192.168.10.1/25 which is an interface of router A
3)Server A is named ‘BLDGBFILESRVR01’ and has an IP address of 192.168.10.145/25
4) PC 2 with an IP address of 192.168.10.200/25 can successfully ping server A
However, when PC 1 pings server A, it receives a destination host unreachable responds. Which of the following is the MOST likely cause?

A. Link from touter A to PC 1 are on different subnets
B. Link from router A to server A is down
C. Link from PC 1 to router A has duplex issues
D. Link from server A top PC 2 is down

Correct Answer: B

Explanation:
PC 1 cannot connect to Server A. PC 1 and Server A are on different subnets that are connected by Router A. PC 1 can connect to Router A; therefore there is no problem with the link or IP address configuration between PC 1 and Router A.
PC 2, which is on the same subnet as Server A, can connect to Server A; therefore Server A is up.
As PC 1 can connect to Router A but cannot connect to Server A, and Server A is up; the problem must be the connection (link) between Router A and Server A.

CompTIA Network+ Question A-23

Peter, a network technician, is setting up a DHCP server on a LAN segment. Which of the following options should Peter configure in the DHCP scope, in order to allow hosts on that LAN segment using dynamic IP addresses, to be able to access the Internet and internal company servers? (Select THREE).

A. Default gateway
B. Subnet mask
C. Reservations
D. TFTP server
E. Lease expiration time of 1 day
F. DNS servers
G. Bootp

Correct Answer: ABF

Explanation:
The question states that the client computers need to access the Internet as well as internal company servers. To access the Internet, the client computers need to be configured with an IP address with a subnet mask (answer B) and the address of the router that connects the company network to the Internet. This is known as the ‘default gateway’ (answer A).
To be able to resolve web page URLs to web server IP addresses, the client computers need to be configured with the address of a DNS server (answer F).

CompTIA Network+ Question A-14

The RAID controller on a server failed and was replaced with a different brand. Which of the following will be needed after the server has been rebuilt and joined to the domain?

A. Vendor documentation
B. Recent backups
C. Physical IP address
D. Physical network diagram

Correct Answer: B

Explanation:
If the RAID controller fails and is replaced with a RAID controller with a different brand the RAID will break. We would have to rebuild a new RAID disk, access and restore the most recent backup to the new RAID disk.
Note: RAID controller is a hardware device or software program used to manage hard disk drives (HDDs) or solid-state drives (SSDs) in a computer or storage array so they work as a logical unit. In hardware-based RAID, a physical controller is used to manage the RAID array.