It gives information about an IPv4 addressing.

1. IPv4 Addresses
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2. IPv4 addresses
• Each computer connected to the internet should be
identified uniquely. The identifier are used for this
purpose is called as the Internet address or IP address.
• The hosts and routers on the Internet have unique IP
addresses.
• The current version of IP is IPv4 whereas the advanced
version is IPv6.
• The IPv4 address is a 32-bit address and it is used for
defining the connection of a host or router to the
Internet. Thus an IP address is an address of the
interface.
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3. Uniqueness of IP addresses
• The IP address is unique and universal. That
means each IP address defines only one
connection to the Internet.
• All the IPv4 addresses are 32-bit long and they
are used in the source and destination address
fields of the IP header.
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4. Address Space
• The IPv4 protocol has an address space. It is
defined as the total number of addresses used
by the protocol.
• If N number of bits are used for defining an
address then the address space will be 2N
addresses.
• The address space of IPv4 is 232
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5. Notation
• The IPv4 addresses can be shown use three
different notations as follows:
1. Binary notations (base 2)
2. Dotted decimal notations (base 256)
3. Hexadecimal notations (base 16)
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6. Dotted decimal notation
• This notation has become popular because of the
two advantages it offers. This notation make the
IPv4 address more compact and easy to read.
• The 32-bit IPv4 address is grouped into groups of
8-bit each separated by decimal points (dots).
• Each 8-bit group is then cnverted into an
equivalent decimal number.
• Each octet (byte) can take a value between 0 to
255. therefore the IPv4 address in the dotted
decimal notation has a range from 0.0.0.0 to
255.255.255.255.
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7. • For example the IPv4 address of
10010001.00001010.00100010.00000011
is denoted in the decimal dotted form as
145.10.34.3
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IP Address 10010001. 00001010. 00100010. 00000011
Dotted decimal 145. 10. 34. 3
145 10 34 3

8. IP Address Assignment
• The network administrator need to assign IP
addresses to the system on their network. This
address needs to be unique one.
• The IP address consists of two parts namely a
network identifier and host identifier.
• All the computers on particular subnet will
have the same network identifier but different
host identifier.
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9. IPv4 Address Format
• A 32-bit IPv4 address consists of two parts. The first part is
called as net id i.e. network identification which identifies
a network on the Internet and second part is called as the
host id which identifies a host on that network.
• Note that the net id and host id are of variable lengths
depending on the class of address.
• Note that class D and E addresses are not divided into net
id and host id.
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net id host id IPv4 address
32 bits