Tutorials

## Free Class A Subnetting tutorial, IP Address Subnetting, how to subnet Class A network

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 A - 4 Bit Subnetting

If we include four bits from the host part to the network part, the subnet mask is changed to 255.240.0.0.

00001010.0000 | 0000.00000000.00000000
11111111.1111 | 0000.00000000.00000000

The four bits added to network part can have sixteen possible values in second 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 10.0.0.0 is divided into sixteen networks, each network has 1048576 total IPv4 addresses and 1048574 usable IPv4 addresses (two IPv4 addresses are used in each subnet to represent the network address and the directed broadcast address).

From the above examples, you can clearly understand how to subnet a Class A network..

Class A IPv4 Subnetting can be summerized as below.
0 255.0.0.0 /8 1 16777214
1 255.128.0.0 /9 2 8388606
2 255.192.0.0 /10 4 4194302
3 255.224.0.0 /11 8 2097150
4 255.240.0.0 /12 16 1048574
5 255.248.0.0 /13 32 524286
6 255.252.0.0 /14 64 262142
7 255.254.0.0 /15 128 131070
8 255.255.0.0 /16 256 65534
9 255.255.128.0 /17 512 32766
10 255.255.192.0 /18 1024 16382
11 255.255.224.0 /19 2048 8190
12 255.255.240.0 /20 4096 4094
13 255.255.248.0 /21 8192 2046
14 255.255.252.0 /22 16384 1022
15 255.255.254.0 /23 32768 510
16 255.255.255.0 /24 65536 254
17 255.255.255.128 /25 131072 126
18 255.255.255.192 /26 262144 62
19 255.255.255.224 /27 524288 30
20 255.255.255.240 /28 1048576 14
21 255.255.255.248 /29 2097152 6
22 255.255.255.252 /30 4194304 2

In this Class A Subnetting Tutorial - Part 2, You have learned how to perform a Class A 4 bit subnetting. Click "Next" to continue.

Jajish Thomason