Day 4 - Chapter 8_ IP Subnetting, Troubleshooting IP, and Intro

Which is true of the IP address 135.20.255.255?

• It is a Class A address.

• It is a broadcast address.

• It is the default gateway address.

• It has a default mask of 255.0.0.0.

Answer explanation

The IP address 135.20.255.255 is a broadcast address for the subnet 135.20.0.0/16, meaning it is used to send data to all devices on that subnet. It is not a Class A address, default gateway, or associated with a default mask of 255.0.0.0.

You have been given an IP address network of 203.23.23.0. You are asked to subnet it for two hosts per network. What is the subnet mask you will need to use to maximize networks?

• 255.255.255.252

• 255.255.255.248

• 255.255.255.240

• 255.255.255.224

Answer explanation

The subnet mask 255.255.255.252 allows for 4 IP addresses per subnet (2 usable for hosts), maximizing the number of subnets. This is ideal for networks requiring only 2 hosts, making it the correct choice.

You require the subnetting of the network address 192.168.1.0 to allow for 10 hosts per subnet while maintaining the maximum number of subnets. What should the subnet mask be?

• 255.255.255.192

• 255.255.255.224

• 255.255.255.240

• 255.255.255.248

Answer explanation

To accommodate 10 hosts, we need at least 4 bits for host addresses (2^4 - 2 = 14). This leaves 4 bits for subnetting in a /28 subnet mask (255.255.255.240), allowing for 16 subnets.

You have been assigned a network ID of 131.44.0.0/16 by your ISP. Your organization needs to use this network ID over four campuses. What mask should be used to subnet it to achieve the goal while maximizing host IP addresses?

• 255.255.128.0

• 255.255.192.0

• 255.255.252.0

• 255.255.255.0

Answer explanation

Using a /18 subnet mask (255.255.192.0) allows for 4 subnets, each with 16382 usable IP addresses, maximizing host capacity while accommodating the four campuses.

What is the CIDR notation for a subnet mask of 255.255.240.0?

• /19

• /20

• /22

• /28

Answer explanation

The subnet mask 255.255.240.0 corresponds to a CIDR notation of /20. This is because the first 20 bits are used for the network part, leaving 12 bits for host addresses.

You have been given an IP address network of 213.43.53.0. You are asked to subnet it for 22 hosts per network. What is the subnet mask you will need to use to maximize networks?

• 255.255.255.252

• 255.255.255.248

• 255.255.255.240

• 255.255.255.224

Answer explanation

To accommodate 22 hosts, we need at least 5 bits for host addresses (2^5-2=30 usable hosts). The subnet mask 255.255.255.224 (or /27) provides 32 addresses (30 usable), maximizing the number of networks.

Which valid IP is in the same network as 192.168.32.61/26?

• 192.168.32.59

• 192.168.32.63

• 192.168.32.64

• 192.168.32.72

Answer explanation

The subnet mask /26 allows for IPs from 192.168.32.0 to 192.168.32.63. Among the options, 192.168.32.59 is within this range, while 192.168.32.63 is the broadcast address, and 192.168.32.64 is in a different subnet.

You are setting up a network in which you need 15 subnetworks... Which subnet mask will you use?

• 255.255.224.0

• 255.255.240.0

• 255.255.248.0

• 255.255.252.0

Answer explanation

To create 15 subnets, you need at least 4 bits (2^4 = 16). The subnet mask 255.255.240.0 (or /20) provides 16 subnets, making it the correct choice for your requirement.

An ISP gives you an IP address of 209.183.160.45/30... Which IP address will be on the ISP side?

• 209.183.160.43/30

• 209.183.160.44/30

• 209.183.160.46/30

• 209.183.160.47/30

Answer explanation

The /30 subnet mask allows for 4 IP addresses: 209.183.160.44 (network), 209.183.160.45 (your IP), 209.183.160.46 (ISP side), and 209.183.160.47 (broadcast). Thus, the ISP side IP is 209.183.160.46.

In the following exhibit, what needs to be changed for Computer A to successfully communicate with Computer B (least effort)?

• Computer A IP

• Computer B IP

• Default gateway for Computer A

• Default gateway for Computer B

Answer explanation

For Computer A to communicate with Computer B, it needs a correct default gateway. This allows it to route packets outside its local network. Changing the default gateway for Computer A is the least effort solution.