Mastering IPv4 subnets and interpreting network and host details from an IP address and subnet mask is essential for understanding IPv4 networks. 

Consider the following table:

Given:

Host IP Address: 10.101.99.228

Original Subnet Mask: 255.0.0.0

New Subnet Mask: 255.255.128.0

Now find:

Number of Subnet Bits

Number of Subnets Created

Number of Host Bits per Subnet

Number of Hosts per Subnet

Network Address of this Subnet

IPv4 Address of First Host on this Subnet

IPv4 Address of Last Host on this Subnet

IPv4 Broadcast Address on this Subnet

Explanation:

Let's check the calculations and ensure the final table is accurate:

1. Host IP Address: 10.101.99.228 (Given)

2. Original Subnet Mask: 255.0.0.0 (Given)

3. New Subnet Mask: 255.255.128.0 (Given)

Now, let's work through the calculations again step-by-step:

Number of Subnet Bits:

·         Original subnet mask is /8 (since 255.0.0.0).

·         New subnet mask is /17 (since 255.255.128.0).

·         Number of Subnet Bits = New subnet mask bits - Original subnet mask bits

o Number of Subnet Bits = 17 - 8 = 9.

Number of Subnets Created:

·         Number of Subnets Created = 2number of subnet bits

o Number of Subnets Created = 29=512 (2^9 = 512)

Number of Host Bits per Subnet:

·         Number of Host Bits per Subnet = Total bits - New subnet mask bits

o Number of Host Bits per Subnet = 32 - 17 = 15.

Number of Hosts per Subnet:

·         Number of Hosts per Subnet = 2number of host bits−2

o Number of Hosts per Subnet = 215−2=32,766

Field Value

Host IP Address 10.101.99.228

Original Subnet Mask 255.0.0.0

New Subnet Mask 255.255.128.0

Number of Subnet Bits 9

Number of Subnets Created 512

Number of Host Bits per Subnet 15

Number of Hosts per Subnet 32,766

How do I find out the Network Address of this Subnet?

To find the network address of a given subnet, you can follow these steps:

1. Convert the IP Address and Subnet Mask to Binary:

o IP Address: 10.101.99.228

o Subnet Mask: 255.255.128.0

2. Perform a Bitwise AND Operation:

o This means comparing each bit of the IP address to the corresponding bit of the subnet mask. If both bits are 1, the resulting bit is 1; otherwise, it's 0.

3. Convert the Result Back to Decimal:

o The resulting binary number after the bitwise AND operation will be your network address.

Let's work through this example:

Step 1: Convert to Binary

·         IP Address: 10.101.99.228

o 10: 00001010

o 101: 01100101

o 99: 01100011

o 228: 11100100

o IP Address (binary): 00001010.01100101.01100011.11100100

·         Subnet Mask: 255.255.128.0

o 255: 11111111

o 255: 11111111

o 128: 10000000

o 0: 00000000

o Subnet Mask (binary): 11111111.11111111.10000000.00000000

Step 2: Perform Bitwise AND Operation

   IP Address: 00001010.01100101.01100011.11100100

   Subnet Mask:   11111111.11111111.10000000.00000000

   -------------------------------------------------

   Network Address: 00001010.01100101.00000000.00000000

Step 3: Convert the Result Back to Decimal

·         Network Address (binary): 00001010.01100101.00000000.00000000

o 00001010: 10

o 01100101: 101

o 00000000: 0

o 00000000: 0

·         Network Address: 10.101.0.0

So, the network address of the subnet for the IP address 10.101.99.228 with the subnet mask 255.255.128.0 is 10.101.0.0.

How do I find out the IPv4 Broadcast Address on this Subnet?

The broadcast address for an IPv4 subnet is determined by setting all host bits to 1. Here's how you can calculate it:

1. Find the Network Address:

o We've already determined the network address: 10.101.0.0.

2. Convert the Network Address and Subnet Mask to Binary:

o Network Address: 10.101.0.0

§  10: 00001010

§  101: 01100101

§  0: 00000000

§  0: 00000000

§  Network Address (binary): 00001010.01100101.00000000.00000000

o Subnet Mask: 255.255.128.0

§  255: 11111111

§  255: 11111111

§  128: 10000000

§  0: 00000000

§  Subnet Mask (binary): 11111111.11111111.10000000.00000000

3. Invert the Subnet Mask to get the Wildcard Mask:

o Wildcard Mask: (Inverted Subnet Mask)

§  00000000.00000000.01111111.11111111

4. Perform a Bitwise OR Operation Between the Network Address and the Wildcard Mask:

   Network Address:         00001010.01100101.00000000.00000000

   Wildcard Mask:         00000000.00000000.01111111.11111111

   -----------------------------------------------------

   Broadcast Address:      00001010.01100101.01111111.11111111

5. Convert the Result Back to Decimal:

o Broadcast Address (binary): 00001010.01100101.01111111.11111111

§  00001010: 10

§  01100101: 101

§  01111111: 127

§  11111111: 255

o Broadcast Address: 10.101.127.255

So, the IPv4 broadcast address for the subnet with the network address 10.101.0.0 and the subnet mask 255.255.128.0 is 10.101.127.255.