Question

You have leased a Class C network whose network ID is 204.188.89.0. You need to divide it into three subnets to correspond to three different departments in your organization.

For each of the four subnets enter the usable Host Address range:

NOTE: enter the host address range using the following format 0.0.0.0-0.0.0.0
Notice the single dash between each IP address.

Host addresses for the first subnet:
Host addresses for the second subnet:
Host addresses for the third subnet:
Host addresses for the fourth subnet:

Answer 1

Given network: 204.188.89.0

As this is from class C network, so subnet mask is 255.255.255.0 and its CIDR is /24

We need to divide the network into three subnets, but number of subnets can only be in power of 2, So network can be subnetted to 4 subnets only not three.

Number of addresses in Class C network = 2^32-24 = 2⁸ = 256

Number of addresses in each subnet = 256/4 = 64 = 2⁶ , so CIDR = 32 - 6 = 26

So in subnet mask, first 26 bits will be 1 and next 6 will be 0 i.e.

11111111.11111111.11111111.11000000

Converting this to decimal it is

255.255.255.192

As each subnet will have 64 addresses,so subnet multiplier = 64(256-192). below are the address ranges.

First Subnet

Number of addresses = 204.188.89.0 - 204.188.89.63

First address of this subnet is subnet address and last address is broadcast address. So usable host range:

204.188.89.1-204.188.89.62

Number of usable hosts = 64 - 2 = 62

Second Subnet

Number of addresses = 204.188.89.64 - 204.188.89.127

First address of this subnet is subnet address and last address is broadcast address. So usable host range:

204.188.89.65-204.188.89.126

Number of usable hosts = 64 - 2 = 62

Third Subnet

Number of addresses = 204.188.89.128 - 204.188.89.191

First address of this subnet is subnet address and last address is broadcast address. So usable host range:

204.188.89.129-204.188.89.190

Number of usable hosts = 64 - 2 = 62

FourthSubnet

Number of addresses = 204.188.89.192 - 204.188.89.255

First address of this subnet is subnet address and last address is broadcast address. So usable host range:

204.188.89.193-204.188.89.254

Number of usable hosts = 64 - 2 = 62