1. IP Addressing

2. IP Addressing IP version 4 – 32 bit addressing
IP Addressing is Logical Addressing
It works on Network Layer (Layer 3)
Two Version of Addressing Scheme
IP version 4 – 32 bit addressing
IP version 6 – 128 bit addressing

3. IP version 4
What is BIT ?
Bit is a value that will represent 0’s or 1’s (i.e. Binary)
32 bits are divided into 4 Octets known as Dotted Decimal Notation
First Octet Second Octet Third Octet Forth Octet

4. IP version 6
128-bit address is divided along 16-bit boundaries, and each 16-bit block is converted to a 4-digit hexadecimal number and separated by colons (Colon-Hex Notation) FEDC:BA98:7654:3210:FEDC:BA98:7654:3210

5. Binary to Decimal Conversion
Taking Example for First Octet :
Total 8 bits, Value will be 0’s and 1’s
i.e. 28 = 256 combination
= 0
= 1
= 2
= 3
= 4
Total IP Address Range to
= 255

6. IP Address Classes Total IP Addressing Scheme is divided
into 5 Classes
CLASS A
CLASS B
CLASS C
CLASS D
CLASS E
LAN & WAN
Multicasting & Newsgroups
Research & Development

7. Priority Bits Concept
To identify the range of each class we will be using Priority Bit Concept
Priority Bit is the left most bits in the First Octet
CLASS A priority bit is 0
CLASS B priority bit is 10
CLASS C priority bit is 110
CLASS D priority bit is 1110
CLASS E priority bit is 1111

8. 0.X.X.X and 127.X.X.X network are reserved
CLASS A Range
For Class A range reserved first bit in
first octet,the value of that bit should not change.
0xxxxxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx
= 0
= 1
= 2
= 3
= 4
Class A Range to
Exception
0.X.X.X and 127.X.X.X network are reserved
= 127

9. CLASS B Range 10xxxxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx 128. 0 . 0 . 0 to
For Class B range reserved first two bit in
first octet,the value of that bit should not change.
10xxxxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx
= 128
= 129
= 130
= 131
= 132
Class B Range to
= 191

10. CLASS C Range 110xxxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx 192. 0 . 0 . 0 to
For Class C range reserved first three bit in
first octet,the value of that bit should not change.
110xxxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx
= 192
= 193
= 194
= 195
= 196
Class C Range to
= 223

11. CLASS D Range 1110xxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx 224. 0 . 0 . 0 to
For Class D range reserved first four bit in
first octet,the value of that bit should not change.
1110xxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx
= 224
= 225
= 226
= 227
= 228
Class D Range to
= 239

12. CLASS E Range 1111xxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx 240. 0 . 0 . 0 to
For Class E range reserved first four bit in
first octet,the value of that bit should not change.
1111xxxx. xxxxxxxx. xxxxxxxx. xxxxxxxx
= 240
= 241
= 242
= 243
= 244
Class E Range to
= 255

13. Octet Format IP address is divided into Network & Host Portion
CLASS A is written as N.H.H.H
CLASS B is written as N.N.H.H
CLASS C is written as N.N.N.H

14. CLASS A Networks & Host Class A Octet Format is N.H.H.H
Network bits : 8 Host bits : 24
No. of Networks
= 28-1 (-1 is Priority Bit for Class A)
= 27
= 128 – 2 (-2 is for 0 & 127 Network)
= 126 Networks
No. of Host
= 224 – 2 (-2 is for Network ID & Broadcast ID) =
= Hosts/Network
CLASS A
126 Networks
&
Hosts/Nw

15. CLASS B Networks & Host Class B Octet Format is N.N.H.H
Network bits : 16 Host bits : 16
No. of Networks
= (-2 is Priority Bit for Class B)
= 214
= Networks
No. of Host
= 216 – 2 (-2 is for Network ID & Broadcast ID) =
= Hosts/Network
CLASS B
16384 Networks
&
65534 Hosts/Nw

16. CLASS C Networks & Host Class C Octet Format is N.N.N.H
Network bits : 24 Host bits : 8
No. of Networks
= (-3 is Priority Bit for Class C)
= 221
= Networks
No. of Host
= 28 – 2 (-2 is for Network ID & Broadcast ID) =
= 254 Hosts/Network
CLASS C
Networks
&
254 Hosts/Nw

17. Network & Broadcast Address
The network address is represented with all bits as ZERO in the host portion of the address
The broadcast address is represented with all bits as ONES in the host portion of the address
Valid IP Addresses lie between the Network Address and the Broadcast Address.
Only Valid IP Addresses are assigned to hosts/clients

18. Example - Class A Class A : N.H.H.H Network Address :
0xxxxxxx
Broadcast Address :
0xxxxxxx
Class A
Network Address
Valid IP Addresses
Broadcast Address

19. Example - Class B 10xxxxxx.xxxxxxxx.00000000.00000000
Class B : N.N.H.H
Network Address :
10xxxxxx.xxxxxxxx
Broadcast Address :
10xxxxxx.xxxxxxxx
Network Address
Class B
Broadcast Address
Valid IP Addresses

20. Example - Class C Class C : N.N.N.H Network Address :
110xxxxx.xxxxxxxx.xxxxxxxx
Broadcast Address :
110xxxxx.xxxxxxxx.xxxxxxxx
Network Address
Class C
Broadcast Address
Valid IP Addresses

21. Private IP Address
There are certain addresses in each class of IP address that are reserved for LAN. These addresses are called private addresses.
They can be used for: home & office networks, ATM machines, networks not connected to Internet.
Class A to
Class B to
Class C to

22. Subnet Mask
Subnet Mask differentiates Network portion and Host Portion
Subnet Mask is been given for host Identification of Network ID
Represent all Network Bit Values with 1
Represent all Host Bit Values with 0

23. What is Subnet ? A portion of network
Which may be a physically independent network
Which share network address with other portion of bigger network

24. What is subnetting ?
Subnetting is essentially the modification of a singal IP network to create two or more logical visible sub section.
It achieve by usesing bits from host portion of the IP address & reserves them to define a Subnet address

25. When subnetting is necessary .
Subnetting is required when one netwrok number needs to be distribute across multiple LAN segement .
Hosts which dominate most of the LAN bandwidth need to isolated.

26. The Fast Way: Subnetting
How many subnets? 2x = number of subnets. x is the number of masked bits, or the 1s.
How many hosts per subnet? 2y – 2 = number of hosts per subnet. y is the number of unmasked bits, or the 0s.
You need to subtract two for the subnet/network address and the broadcast address, which are not valid hosts.
What are the valid subnets? 256 – subnet mask = block size, or increment number.
What’s the broadcast address for each subnet?
the broadcast address is always the number right before the next subnet.
What are the valid hosts?
These are the numbers between the subnet and broadcast address.

27. Class C network of /24
You can start by looking at the subnet requirement. In order to create the five needed subnets you would need to use three bits from the Class C host bits. Two bits would only allow you four subnets (22).
Since you need three subnet bits, that leaves you with five bits for the host portion of the address. How many hosts will this support? 25 = 32 (30 usable). This meets the requirement.

28. Contt.. Host address range 1 to 30 Host address range 33 to 62
netA: /27
netB: /27
netC: /27
netD: /27
netE: /27
Host address range 1 to 30
Host address range 33 to 62
Host address range 65 to 94
Host address range 97 to 126
Host address range 129 to 158

29. VLSM-Variable Length Subnet Mask
In all of the previous examples of subnetting you will notice that the same subnet mask was applied for all the subnets. This means that each subnet has the same number of available host addresses. You may need this in some cases, but, in most cases, having the same subnet mask for all subnets ends up wasting address space.
For example, in the solution above, a class C network was split into eight equal-size subnets; however, each subnet did not utilize all available host addresses, which results in wasted address space. The figure below illustrates this wasted address space.

30. VLSM netA: 204.15.5.0/27 netB: 204.15.5.32/27 netC: 204.15.5.64/27
Variable Length Subnet Masks (VLSM) allows you to use different masks for each subnet, thereby using address space efficiently.
netA: /27
netB: /27
netC: /27
netD: /27
netE: /27

31. VLSM netA: requires a /28 (255.255.255.240) mask to support 14 hosts
netB: requires a /27 ( ) mask to support 28 hosts
netC: requires a /30 ( ) mask to support 2 hosts
netD*: requires a /28 ( ) mask to support 7 hosts
netE: requires a /27 ( ) mask to support 28 hosts 
Solution :---
netB: /27 host address range 1 to 30
netE: /27 host address range 33 to 62
netA: /28 host address range 65 to 78
netD: /28 host address range 81 to 94
netC: /30 host address range 97 to 98