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+ Simulation 4

After recent changes to the pictured network, several users are unable to access the servers. Only PC1, PC2, PC3, and PC4 are configurable. You can only change the adapter configurations to each PC.

Correct Answer:

On PC3, change the subnet mask to 255.255.255.0. When it is set to 255.255.255.128, then the PC with a .129 address will not be on the same subnet as the default gateway which is .1
On PC4, change the default gateway to 10.0.2.1. It has been incorrectly set as 10.1.2.1.

On this simulation, you will be asked to test connectivity after fixing the issues. You MUST ping the other three computers on EACH computer (i.e. from PC1, ping PC2, PC3, PC4, and from PC2, ping PC1, PC3 and PC4, etc)

CompTIA Network+ Simulation 2

Corporate headquarters provided your office a portion of their class B subnet to use at a new office location. Allocate the minimum number of addresses (using CIDR notation) needed to accommodate each department.

Range Give: 172.30.232.0/24
Sales: 57 devices
HR: 23 devices
IT: 12 devices
Finance: 32 devices
Marketing: 9 devices

After accommodating each department, identify the unused portion of the subnet by responding to the question on the graphic. All drop downs must be filled. Instructions: When the simulation is complete, please select the Done button to submit.

All Networks have the range from /0 to/32

Correct Answer:


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.

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), we can determine that the following subnets should be configured:

Sales network – /26 – This will provide up to 62 usable IP addresses (64-2 for subnet and broadcast IP) HR network – /27 – This will provide for up to 30 usable IP’s (32-2)
IT – /28 – This will provide for up to 14 usable IP’s (16-2)
Finance – /26 – Note that a /27 is 32 IP addresses but 2 of those are reserved for the network and broadcast IP’s and can’t be used for hosts. Marketing – /28
If we add up how many IP blocks are used that is 64+32+16+64+16=192. A /24 contains 256 IP addresses, so 256-192=64.
So the last unused box should be a /26, which equates to 64 addresses

CompTIA A+ Question L-43

255.255.0.0 is the standard subnet mask for which of the following IP classes?

A. Class A
B. Class B
C. Class C
D. Class D

Correct Answer: B

Explanation:
255.255.0.0 is a class B subnet mask. http://www.webopedia.com/TERM/S/subnet_mask.html

CompTIA A+ Question K-80

Which of the following network classes is identified by a subnet mask of 255.240.0.0?

A. Class A
B. Class B
C. Class C
D. Class D

Correct Answer: B

CompTIA A+ Question J-69

Which of the following is an advantage of dynamic addressing?

A. To allow hosts with different subnet masks to communicate
B. To prevent host computers from staying at one address
C. To allow easy addition of new hosts to the network
D. To allow hosts to use multiple addresses at the same time

Correct Answer: C

CompTIA A+ Question I-72

Which of the following is another description of a default gateway?

A. The DNS server
B. The inverse subnet mask
C. The route of last resort
D. The subnet network address

Correct Answer: C

CompTIA A+ Question G-33

A computer technician is installing a new wireless router for a small office. The office already has an internal device that assigns addresses to users. Which of the following functions needs to be disabled on the router to prevent conflicts?

A. DMZ capability
B. MAC filtering capability
C. Network Address Translation
D. DHCP server functionality

Correct Answer: D

Explanation:
DHCP automatically assigns IP address, subnet mask and default gateway to provide access to workstations. Disable DHCP server before installing a wireless router so that you can configure it without DHCP assigning IP addresses to other computers.