/24 subnet mask with example
/24 subnet mask is the default subnet mask of the class c network which means all IP addresses in the range from 192.0. 0.0 to 223.255.255.0 has the subnet mask of 255.255.255.0.
/24 in subnet mask in binary is
11111111.11111111.11111111.00000000
It has 4 octets, all ones represent a network and Zeroes represent a host so /24 subnet mask gives us 256 host addresses. We can use 254 of those host addresses as two are reserved for network ID and broadcast address.
This address range is the most common range used in private networks because it gives relatively fewer host addresses which reduces the requirement of subnetting.
However, we can further create more networks by changing the default subnet mask.
If we want to create more networks then we can change the existing host bits to network bits then a new subnet mask will be created however it will reduce the number of host IPs available to be assigned to the devices.
If we have a default class b network address with the default subnet mask of /16 then we can change it to /24 to create a subnetted network address.
For E.g. 150.150.0.0 address with a subnet mask of 255.255.0.0 now, we will change the host bits to network bits so the new subnet mask will be 255.255.255.0 and the IP range will be from 150.150.0.0 to 150.150.0.255.
Most of the home routers available in the markets use the class c range to assign an IP address to the hosts and we use the IP address from the same network to manage the device.
Example
Creating more networks from IP address range 192.168.1.0/24 to 192.168.1.255
To create two subnets, we have to convert one host bit to a network bit so the new subnet mask will be 255.255.255.128 or /25 in CIDR notation
IP ranges will be as below
192.168.1.0 – 192.168.1.127
192.168.1.128 – 192.168.1.255
Now, we have to use the new subnet mask while assigning the IP addresses to the end devices. Using the /24 subnet mask will place the devices in one network however using the /25 subnet mask will place the host in a different subnet if we use the address from the above two ranges.
