## How do I calculate how many subnets I need?

To calculate the number of possible subnets, use the formula 2n, where n equals the number of host bits borrowed. For example, if three host bits are borrowed, then n=3. 23 = 8, so eight subnets are possible if three host bits are borrowed.

## How do you calculate class subnetting?

Valid subnet address: To figure out the valid subnet address, simply subtract the subnet mask from 256. For example, if you had a Class A mask of 255.240. 0.0, the equation would be 256-240=16….The first available subnet is:

1. Subnet: 10.0. 0.0.
3. Valid host range: 10.0. 0.1 through 10.0. 127.254.

Why subnetting is required?

Why is subnetting necessary? Because an IP address is limited to indicating the network and the device address, IP addresses cannot be used to indicate which subnet an IP packet should go to. Routers within a network use something called a subnet mask to sort data into subnetworks.

### How do you subnet a Class B?

2-2=510 subnets. 2-2=126 hosts per subnet. For the third octet, the mask would be 256-255=1, 2, 3, 4, 5, 6, etc. For the fourth octet, the mask would be 256-128=128, which is one subnet if it is used….Subnetting a Class B network address.

Subnet 64.0 128.0

### Can subnetting be done in Class D and E?

Subnetting cannot be done in class D and E. In class A, B and C first 8, 16 and 24 bits are reserved for network address respectively. In all three classes last 2 bits are reserved for host addresses. If we exclude reserved network bits and host bits from total IP bits, we will get Subnetting eligible host bits.

Which IP classes are used for subnetting?

There are five IP classes A, B, C, D and E. From these, only first three classes A, B and C are used in Subnetting. Subnetting cannot be done in class D and E. In class A, B and C first 8, 16 and 24 bits are reserved for network address respectively. In all three classes last 2 bits are reserved for host addresses.

#### What is a Class B subnet?

Class B Subnets. By default, using Classful Networking, 14 bits are used as Network bits providing (2 14) 16384 Networks and (2 16-2) 65534 Hosts. Class B IP Addresses can be subnetted the same way as Class A addresses, by borrowing bits from Host bits. Below is given all possible combination of Class B subnetting:

#### What is subnetting and why do we use it?

By using subnetting, one single Class A IP address can be used to have smaller sub-networks which provides better network management capabilities.