2. CONTENTS
2
Introduction
Working with IP Addressing
IP Address classes
Subnet Mask
Subnetting , Subnet and Subnet Mask
3. Introduction
IP Address is Internet Protocol which is used
to identified the HOST, NETWORK
IP Address is 32 Bit Logical Address
IP Address is divided in four octet which is
separated by DOT (.)
An octet is a set of 8 bits . Eg 192.128.56.43
3
4. Working with IP Addressing
Two of the most
common questions you
are going to face when
dealing with IP
addresses are:
• What’s the network?
• What’s the host?
• How dow we figure this
out?
192.168.100.80/26
????
4
5. First, convert the IP address
into binary. This is easier
than it looks.
Work with one octet at a
time.
Divide by two, farm out the
remainder on the side.
The bottom is the binary
MSD, the top the binary
LSD.
192
divide by 2
remainder
96 0
divide by 2
remainder
48 0
divide by 2
remainder
24 0
divide by 2
remainder
12 0
divide by 2
remainder
6 0
divide by 2
remainder
3 0
divide by 2
remainder
1 1
divide by 2
remainder
0 1
Left Right
Working with IP Addressing
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6. Working with IP Addressing
Write down the IP
address.
11000000 10101000 01100100 01010000
192 168 100 80
If you have a prefix
length, just wrote
down the number of
1’s. If you have a
network mask,
computer the binary
as with the IP
address.
11111111 11111111 11111111 11000000
8 +8 +8 +2 == 26
AND these two. 11000000 10101000 01100100 01000000
Convert back to
dotted decimal. This
is the network
address.
192 168 100 64
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7. Working with IP Addressing
Write down the IP
address.
11000000 10101000 01100100 01010000
192 168 100 80
If you have a prefix
length, just wrote
down the number of
1’s. If you have a
network mask,
computer the binary
as with the IP
address.
11111111 11111111 11111111 11000000
8 +8 +8 +2 == 26
NOR these two. 00000000 00000000 00000000 00010000
Convert back to
dotted decimal. This
is the host address.
0 0 0 16
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8. IP Address Classes
IP addresses are divided into 5 classes, each of
which is designated with the alphabetic letters A to
E.
Class D addresses are used for multicasting.
Class E addresses are reserved for testing & some
mysterious future use.
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9. The 32 bits of the IP address are divided into Network & Host
portions, with the octets assigned as a part of one or the
other.
Network & Host Representation
By IP Address Class
Class Octet1 Octet2 Octet3 Octet4
Class A Network Host Host Host
Class B Network Network Host Host
Class C Network Network Network Host
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10. Subnet Mask
With the rapid growth of the internet & the ever-increasing
demand for new addresses, the
standard address class structure has been
expanded by borrowing bits from the Host
portion to allow for more Networks.
Under this addressing scheme, called
Subnetting, separating the Network & Host
requires a special process called Subnet
TMhaes skuinbgn.et masking process was developed to
identify & extract the Network part of the
address.
A subnet mask, which contains a binary bit
pattern of ones & zeros, is applied to an address
to determine whether the address is on the local
Network.
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11. Default Standard Subnet
MaThsekres are default standard subnet masks for
Class A, B and C addresses:
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12. Subnetting, Subnet & Subnet
MasSukbnetting, a subnet & a subnet mask are all
different.
Subnetting is the process of dividing a network
& its IP addresses into segments, each of
which is called a subnetwork or subnet.
The subnet mask is the 32-bit number that
the router uses to cover up the network
address to show which bits are being used to
identify the subnet.
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