A firm is assigned the network part 128.171. It selects a 8-bit subnet part. a) Draw the bits for the four octets of the IP address of the first host on the first subnet. (Hint: Use Windows Calculator.)
b) Convert this answer into dotted decimal notation.
c) Draw the bits for the second host on the third subnet. (In binary, 2 is 10, while 3 is 11.)
d) Convert this into dotted decimal notation.
e) Draw the bits for the last host on the third subnet.
f) Convert this answer into dotted decimal notation.
Remember for any type of address the first address 00000000(0) and last address 11111111(255) are not used, therefore first host address begins with 1 and last usuable host is 254 same goes for the subnet address.
Solution:
a)10000000.10101011.00000001.00000001
b)128.171.1.1
c)10000000.10101011.00000011.00000010
d)128.171.3.2
e)10000000.10101011.00000011.11111110
f)128.171.3.254
a) To find the bits for the four octets of the IP address of the first host on the first subnet:
The network part is 128.171, which in binary is represented as:
Network: 10000000.10101011
For an 8-bit subnet part, the subnet mask is:
Subnet Mask: 11111111.00000000
To find the bits for the host part on the first subnet, assign the subnet identifier (in this case, 0) to the leftmost bits of the host part:
Host: 00000000
Combining the network part and the host part, the binary representation of the IP address of the first host on the first subnet is:
10000000.10101011.00000000.00000000
b) To convert the binary representation into dotted decimal notation, convert each octet from binary to decimal:
128.171.0.0
c) To find the bits for the second host on the third subnet:
The subnet identifier for the third subnet is 2 in binary, which is represented as:
Subnet Identifier: 00000010
To find the bits for the host part of the second host on the third subnet, increment the subnet identifier by 1:
Host: 00000011
Combining the network part and the host part, the binary representation of the IP address of the second host on the third subnet is:
10000000.10101011.00000010.00000011
d) To convert the binary representation into dotted decimal notation:
128.171.2.3
e) To find the bits for the last host on the third subnet:
Since the subnet part uses 8 bits, there are 256 subnets (2^8 = 256) and each subnet can have 2^8 - 2 hosts (excluding the network and broadcast addresses). Therefore, the last host on the third subnet would have the host identifier of 256 - 2 - 1 = 253.
To find the bits for the host part of the last host on the third subnet, assign the host identifier 253 to the host part:
Host: 11111101
Combining the network part and the host part, the binary representation of the IP address of the last host on the third subnet is:
10000000.10101011.00000010.11111101
f) To convert the binary representation into dotted decimal notation:
128.171.2.253
To get the answers to these questions, we need to understand how IP addressing and subnetting work. Let's go through each of the questions step by step:
a) To determine the IP address of the first host on the first subnet, we need to assign the host portion of the IP address. Since 8 bits are available for the subnet part, there are 2^8 = 256 subnets possible. The first subnet would have all zeros in the subnet part, except for the last bit which represents the host portion. Therefore, the bits for the IP address of the first host on the first subnet would be:
```
Network Part: 10000000 (128)
Subnet Part: 00000000 (0)
Host Part: 00000001 (1)
```
b) To convert this into dotted decimal notation, we group the bits into four octets and convert each octet into decimal. The IP address of the first host on the first subnet would be:
```
128.0.0.1
```
c) To determine the IP address of the second host on the third subnet, we need to increment the host portion by 1. The third subnet has a subnet part of '11' in binary, which means the first two bits in the host part are fixed. Therefore, the bits for the IP address of the second host on the third subnet would be:
```
Network Part: 10000000 (128)
Subnet Part: 00000011 (3)
Host Part: 00000010 (2)
```
d) Converting this into dotted decimal notation, we get:
```
128.0.3.2
```
e) To determine the IP address of the last host on the third subnet, we need to set all the bits in the host part to '1'. The bits for the IP address of the last host on the third subnet would be:
```
Network Part: 10000000 (128)
Subnet Part: 00000011 (3)
Host Part: 00000011 (3)
```
f) Converting this into dotted decimal notation, we get:
```
128.0.3.3
```
By following these steps, you can find the answers to the given questions.