Calculate the number of subnets and hosts per subnet given an IP address, original subnet mask, and new subnet mask.

The number of subnet bits is the difference between the new network bits and the original network bits.

$$\text{Number of Subnet Bits} = \text{New CIDR} - \text{Original CIDR} = 27 - 24 = 3$$

• Number of Subnet Bits: 3

The number of subnets created is $2^{\text{number of subnet bits}}$.

$$\text{Number of Subnets Created} = 2^3 = 8$$

• Number of Subnets Created: 8

An IPv4 address has 32 bits. The number of host bits is $32 - \text{new network bits}$.

$$\text{Number of Host Bits per Subnet} = 32 - 27 = 5$$

• Number of Host Bits per Subnet: 5

The number of usable hosts per subnet is $2^{\text{number of host bits}} - 2$ (subtracting the network address and broadcast address).

$$\text{Number of Hosts per Subnet} = 2^5 - 2 = 32 - 2 = 30$$

• Number of Hosts per Subnet: 30

To find the network address, perform a bitwise AND operation between the Host IP Address and the New Subnet Mask.
Host IP: 192.168.200.139
New Subnet Mask: 255.255.255.224
The first three octets are straightforward: 192.168.200.
For the fourth octet:
Host IP fourth octet (139): $10001011_2$
Subnet Mask fourth octet (224): $11100000_2$
Bitwise AND:

$$\begin{array}{c} 10001011_2 \\ \text{AND } 11100000_2 \\ \hline 10000000_2 \end{array}$$

$10000000_2$ is 128 in decimal.
So, the Network Address is 192.168.200.128.

• Network Address of this Subnet: 192.168.200.128

The first host address is the network address plus one.

$$\text{First Host Address} = 192.168.200.128 + 1 = 192.168.200.129$$

• IPv4 Address of First Host on this Subnet: 192.168.200.129

The block size for the fourth octet is $256 - 224 = 32$.
The subnets in the fourth octet are multiples of 32: 0, 32, 64, 96, 128, 160, 192, 224.
Since the host IP 139 falls into the 128 block, the next network address is 160.
The broadcast address for the 192.168.200.128 subnet is one less than the next network address.

$$\text{Broadcast Address} = 192.168.200.160 - 1 = 192.168.200.159$$

• IPv4 Broadcast Address on this Subnet: 192.168.200.159

The last host address is the broadcast address minus one.

$$\text{Last Host Address} = 192.168.200.159 - 1 = 192.168.200.158$$

• IPv4 Address of Last Host on this Subnet: 192.168.200.158

Here is the completed table:

Find:	Answer:
Number of Subnet Bits	3
Number of Subnets Created	8
Number of Host Bits per Subnet	5
Number of Hosts per Subnet	30
Network Address of this Subnet	192.168.200.128
IPv4 Address of First Host on this Subnet	192.168.200.129
IPv4 Address of Last Host on this Subnet	192.168.200.158