OUTCOME OF TODAY’S LECTURE

Completion of this lecture, you all will be able to understand:

 Sunnetting the given network based on the host requirements.

WHAT IS SUBNETTING

 Subnetting is the process of dividing a large network into smaller networks

called "subnets."
 Subnets provide each group of devices with their own space to communicate,
which ultimately helps the network to work easily.
 This also boosts security and makes it easier to manage the network, as each
subnet can be monitored and controlled separately

1st octet of Default Subnet Network Number Maximum

Class of nodes in a
IP address Mask / Host
networks network
A 1 - 126 255.0.0.0 N.H.H.H 126 16,777,214

B 128 - 191 255.255.0.0 N.N.H.H 16,384 65,534

C 192 - 223 255.255.255.0 N.N.N.H 2,097,152 254

D 224 - 239 - - - -

E 240 - 254 - - - -

SUBNETTING — 5 STEPS

STEP 1: Identify the class of the IP address and note the Default Subnet Mask.
STEP 2: Convert the Default Subnet Mask into Binary.
STEP 3: Note the number of hosts required per subnet and find the Subnet
Generator (SG) and octet position.
STEP 4: Generate the new subnet mask
 STEP 5: Use the SG and generate the network ranges (subnets) in the
appropriate octet position.
EXAMPLE PROBLEM

Problem: Subnet the IP addresses 216.215.0 into 30 hosts in each subnet.

Solution
STEP 1
Identify the class of the IP address

1st octet of Default Subnet

Class
IP address Mask

A 1 - 126 255.0.0.0

B 128 - 191 255.255.0.0

C 192 - 223 255.255.255.0

Default Subnet Mask.

1st octet of Default Subnet

Class
IP address Mask

C 192 - 223 255.255.255.0

STEP 2: Convert the Default Subnet Mask into Binary.

Decimal 255 255 255 0

Binary 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0

STEP 3: Note the number of hosts required per subnet and find the Subnet
Generator (SG) and Octet Position.
NUMBER OF HOSTS/SUBNET: 30
 CONVERSION METHOD-5 bits used

16 8 4 2 1

1 1 1 1 0

16+8+4+2=30

SUBNET GENERATOR: 32

Decimal 255 255 255 0

Binary 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0

5 4 3 2 1

Decimal 20 21 22 23 24 25 26 27 28

Binary 0 2 4 8 16 32 64 128 256

OCTET POSITION: 4

Decimal 255 255 255 0

Binary 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0

Octet
Positio 1 2 3 4
n
 STEP 4: Generate the new subnet mask
Decimal 255 255 255 0

Binary
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0

No of 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 25 26 27
1 24
ones

27 ones

128 64 32 16 8 4 2 1

1 1 1 0 0 0 0 0

128+64+32=224

Hence the New Subnet mask is 255.255.255.224/27

STEP 5: Generate the network ranges (subnets)

216.215.0 216.215.31

216.215.32 216.215.63

216.215.64 216.215.95

216.215.96 216.215.127

216.215.128 216.215.159

And so on
Reference Video: https://www.youtube.com/watch?v=qulRjRFavJI

HOME TASK PROBLEM:

Problem: Subnet the IP addresses 112.215.0 into 25 hosts in each subnet.