Tutorials

## Free Class B Subnetting Tutorials, How to subnet Class B network, IPv4 address subnetting

External Resources

This lesson is only a part of a series of IPv4 subnetting lessons. Please visit the below links to learn IPv4 subnetting completely.

• Class C Subnetting Tutorial - Part 1
• Class C Subnetting Tutorial - Part 2
• Class B Subnetting Tutorial - Part 1
• Class B Subnetting Tutorial - Part 2
• Class A Subnetting Tutorial - Part 1
• Class A Subnetting Tutorial - Part 2
• Variable Length Subnet Masking (VLSM)
• Supernetting

### Class B - 4 Bit Subnetting

If we include four bits from the host part to the network part, the subnet mask is changed to 255.255.240.0.

10101100.00010000.0000 | 0000.00000000
11111111.11111111.1111 | 0000.00000000

The four bits added to network part can have sixteen possible values in third octet and that are 0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000, 1001, 1010, 1011, 1100, 1101, 1110, 1111.

SN No Description Binaries Decimal

The network 172.16.0.0 is divided into sixteen networks, each network has 4096 total IPv4 addresses and 4094 usable IPv4 addresses (two IPv4 addresses are used in each subnet to represent the network address and the directed broadcast address). The subnet mask is 255.255.240.0.

Class B Subnetting can be summerized as below.

0 255.255.0.0 /16 1 65534
1 255.255.128.0 /17 2 32766
2 255.255.192.0 /18 4 16382
3 255.255.224.0 /19 8 8190
4 255.255.240.0 /20 16 4094
5 255.255.248.0 /21 32 2046
6 255.255.252.0 /22 64 1022
7 255.255.254.0 /23 128 510
8 255.255.255.0 /24 256 254
9 255.255.255.128 /25 512 126
10 255.255.255.192 /26 1024 62
11 255.255.255.224 /27 2048 30
12 255.255.255.240 /28 4096 14
13 255.255.255.248 /29 8192 6
14 255.255.255.252 /30 16384 2

In this Class B Subnetting tutorial Part - 2, you have learned how perform a Class B 4 bit Subnetting. To view Class A Subnetting Tutorials - Part 1, Click "Next".

Jajish Thomason