Introduction to Networking(Yarnfield)

Classful subnetting

Objective To cover the subnetting process Be able to subnet from a variety of

information

Subnetting The process of dividing a network up into

subnets and to assign each subnet a valid network IP address, and the hosts on that subnet valid IP addresses

Subnet 1

Subnet 3

Subnet 2

We need to find out How many subnets does the subnet mask

provide? How many valid hosts per subnet are

available? What are the valid subnets? What is the broadcast address of each

subnet? What are the valid hosts in each subnet?

We need An IP address to subnetAnd The number of subnets we wish to makeOr The subnet maskOr The number of borrowed bits

Example

192.5.5.35255.255.255.224

Example IP address: 192.5.5.35 Subnet mask: 255.255.255.224 Work out1. Network ID Class2. Major network address3. Major broadcast address4. First host of the major network5. Last host of the major network

Class C

192.5.5.0

192.5.5.255

192.5.5.1

192.5.5.254

Example IP address: 192.5.5.35 Subnet mask: 255.255.255.224 Now we need to work out the subnet

information1. Number of subnet bits2. Number of host bits3. Subnet address for the given host IP address

4. Range of host addresses for this subnet

5. Broadcast address for this subnet

3 subnet bits

5 host bits

192.5.5.32

192.5.5.33 – 192.5.5.62

192.5.5.63

Example IP address: 192.5.5.35 Subnet mask: 255.255.255.224 Now we need to find other subnet information1. Total number of useable subnets2. Number of valid host IP addresses per subnet3. Convert given subnet mask to binary

4. Convert given host IP address to binary

5. Subnetwork address with slash (/) mask for the assigned subnet

6

30

11111111.11111111.11111111.11100000

11000000.00000101.00000101.00100011

192.5.5.32 / 27

Exercise IP address 202.168.2.40 Subnet mask 255.255.255.240 Find out:1. Network ID Class2. Major network address3. Major broadcast address4. First host of the major network5. Last host of the major network6. Number of subnet bits7. Number of host bits8. Subnet address for the given host IP address4. Range of host addresses for this subnet5. Broadcast address for this subnet6. Total number of useable subnets7. Number of valid host IP addresses per subnet8. Convert given subnet mask to binary4. Convert given host IP address to binary5. Subnetwork address with slash (/) mask for the assigned subnet

Questions... ... are there any?