VLSM Design for a New Remote Branch Office

A company is expanding and building a new remote branch office.

Marketing will need 78 IP addresses, finance will need 150 IP addresses, legal will need 39 IP addresses, and R&D will need 12 IP addresses.

The network administrator gives the technician a network of 172.16.48.0/23 and wants the technician to use VLSM for the design.

Which of the following are possible solutions? (Choose three.)

A.

The marketing department should receive a /25 network.

B.

The R&D department should have 172.16.49.207 as a broadcast address.

C.

The R&D department should receive a /27 network.

D.

The finance department should have 172.16.49.127 as a broadcast address.

E.

The marketing department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190.

F.

The legal department should have a first usable IP address of 172.16.49.190

G.

The legal department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190.

H.

The R&D department should have a last usable IP address of 172.16.49.190.

ABG.

To solve this question, we need to use Variable Length Subnet Masking (VLSM) to allocate the required number of IP addresses to each department. We are given a network of 172.16.48.0/23, which has a subnet mask of 255.255.254.0. This means we have 9 bits available for subnetting, allowing us to create up to 512 subnets.

First, we need to determine how many IP addresses each department requires:

Marketing: 78 IP addresses (2^7 - 2) Finance: 150 IP addresses (2^8 - 2) Legal: 39 IP addresses (2^6 - 2) R&D: 12 IP addresses (2^4 - 2)

Next, we need to assign subnets to each department. We will start with the largest department, which is Finance, and work our way down to the smallest department, which is R&D.

1. Finance: We need to allocate a subnet that can accommodate 150 IP addresses. The closest subnet size that can accommodate this requirement is a /24 subnet (256 addresses). However, we can't use a /24 subnet because it will waste too many IP addresses. Therefore, we will use a /25 subnet, which provides 128 addresses. This will be the first subnet and will have the network address of 172.16.48.0/25.

2. Marketing: We need to allocate a subnet that can accommodate 78 IP addresses. The closest subnet size that can accommodate this requirement is a /7 subnet (128 addresses), but this will waste too many IP addresses. Therefore, we will use a /25 subnet, which provides 128 addresses. This will be the second subnet and will have the network address of 172.16.48.128/25.

3. Legal: We need to allocate a subnet that can accommodate 39 IP addresses. The closest subnet size that can accommodate this requirement is a /6 subnet (64 addresses), but this will waste too many IP addresses. Therefore, we will use a /27 subnet, which provides 32 addresses. This will be the third subnet and will have the network address of 172.16.49.0/27.

4. R&D: We need to allocate a subnet that can accommodate 12 IP addresses. The closest subnet size that can accommodate this requirement is a /4 subnet (16 addresses), but this will waste too many IP addresses. Therefore, we will use a /28 subnet, which provides 16 addresses. This will be the fourth subnet and will have the network address of 172.16.49.16/28.

Now, we can answer the questions:

A. The marketing department should receive a /25 network.

• This is correct. We assigned the marketing department a /25 subnet.

B. The R&D department should have 172.16.49.207 as a broadcast address.

• This is incorrect. The last usable IP address for the R&D subnet is 172.16.49.14.

C. The R&D department should receive a /27 network.

• This is incorrect. We assigned the R&D department a /28 subnet.

D. The finance department should have 172.16.49.127 as a broadcast address.

• This is incorrect. The broadcast address for the finance subnet is 172.16.48.127.

E. The marketing department should have usable IPs ranging from 172.16.49.129 to 172.16.49.190.

• This is correct. The usable IP addresses for the marketing subnet are 172.16.48.129 to 172.16.48.190.

F. The legal department should