CompTIA Network+ Question B-91

A company has a network with three switches, each one with eight ports. The switch is connected to a router that has a hub with four computers plugged into one of its interfaces. How many broadcast domains are present in this company’s network

A. 1
B. 2
C. 5
D. 16
E. 28

Correct Answer: B

CompTIA Network+ Question B-86

A network technician is performing a tracert command to troubleshoot a website-related issue. The following output is received for each hop in the tracert:
1 * * * Request timed out.
2 * * * Request timed out.
3 * * * Request timed out.
The technician would like to see the results of the tracert command. Which of the following will allow the technician to perform tracert on external sites but not allow outsiders to discover information from inside the network?

A. Enable split horizon to allow internal tracert commands to pass through the firewall
B. Enable IGMP messages out and block IGMP messages into the network
C. Configure the firewall to allow echo reply in and echo request out of the network
D. Install a backdoor to access the router to allow tracert messages to pass through

Correct Answer: C

Explanation:
Tracert makes use of ICMP echo packets to trace the route between two hosts. For the command to be successful, the firewall has to allow incoming echo replies and outgoing echo requests.

CompTIA Network+ Question B-85

A network technician has just installed a TFTP server on the administrative segment of the network to store router and switch configurations. After a transfer attempt to the server is made, the process errors out. Which of the following is a cause of the error?

A. Only FTP can be used to copy configurations from switches
B. Anonymous users were not used to log into the TFTP server
C. An incorrect password was used and the account is now locked
D. Port 69 is blocked on a router between the network segments

Correct Answer: D

Explanation:
The question states that the TFTP server is installed on the “administrative segment of the network”. This implies that the network has multiple segments (subnets) and TFTP server is on a different network segment to other computers.
For a computer on one subnet to connect to a computer on a different subnet, a router is required to route traffic between the two subnets. Routers often include firewalls so they can be configured to allow specific traffic to be routed between the subnets and block unwanted traffic.
TFTP uses UDP port 69. The most likely cause of the connection timeout error in the question is that the firewall has not been configured to allow traffic using UDP port 69.

CompTIA Network+ Question B-49

A technician, Peter, has been tasked with assigning two IP addresses to WAN interfaces on connected routers. In order to conserve address space, which of the following subnet masks should Peter use for this subnet?

A. /24
B. /32
C. /28
D. /29
E. /30

Correct Answer: E

Explanation:
An IPv4 address consists of 32 bits. The first x number of bits in the address is the network address and the remaining bits are used for the host addresses. The subnet mask defines how many bits form the network address and from that, we can calculate how many bits are used for the host addresses.
In this question, the /30 subnet mask dictates that the first 30 bits of the IP address are used for network addressing and the remaining 2 bits are used for host addressing. The formula to calculate the number of hosts in a subnet is 2n – 2. The “n” in the host’s formula represents the number of bits used for host addressing. If we apply the formula (22 – 2), a /30 subnet mask will provide 2 IP addresses.

CompTIA Network+ Question B-29

A network technician is using telnet to connect to a router on a network that has been compromised. A new user and password has been added to the router with full rights. The technician is concerned that the regularly used administrator account has been compromised. After changing the password on all networking devices, which of the following should the technician perform to prevent the password for the administrator account from being sniffed on the network?

A. Use SNMPv1 for all configurations involving the router
B. Ensure the password is 10 characters, containing letter and numbers
C. Copy all configurations to routers using TFTP for secuirty
D. Only allow administrators to access routers using port 22

Correct Answer: D

CompTIA Network+ Question B-28

Which of the following requires the network administrator to schedule a maintenance window?

A. When a company-wide email notification must be sent.
B. A minor release upgrade of a production router.
C. When the network administrator’s laptop must be rebooted.
D. A major release upgrade of a core switch in a test lab.

Correct Answer: B

Explanation:
During an update of a production router the router would not be able to route packages and the network traffic would be affected. It would be necessary to announce a maintenance window.
In information technology and systems management, a maintenance window is a period of time designated in advance by the technical staff, during which preventive maintenance that could cause disruption of service may be performed.

CompTIA Network+ Question B-24

A telecommunications provider has just deployed a new OC-12 circuit at a customer site. While the circuit showed no errors from the provider end to the customer’s demarcation point, a network administrator is trying to determine the cause of dropped packets and errors on the circuit. Which of the following should the network administrator do to rule out any problems at Layer 1? (Choose two.)

A. Use a loopback at the demark and router, and check for a link light
B. Use an OTDR to validate the cable integrity
C. Use a pinout tester to validate the cable integrity
D. Use a multimeter to validate the cable integrity
E. Check for any devices that may be causing EMI on the cable
F. Clean the cables to be sure they are free of dust and debris

Correct Answer: AB

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