Introduction to IP addressing
IP address is the
addressing system used in network to identify network devices, host
etc. its a unique way which repetition is not allowed especially on
the internet and within LAN local area network. LAN
is group of devices on the same network
address that connect to the same network device.
Types of IP address
- IPv4 (IP version 4)
- IPv6 (IP version 6)
IPv4 is the most
commonly used IP address, its defined as a 32bit address which can
contains up to 4,294,967.296 four billion, two hundred and ninety
four million, nine hundred and sixty seven thousand two hundred and
ninety six addresses. Wow it
sound many! Can we actually exhaust this addresses? The answer is
capital YES! These addresses has already been exhausted. Billions of
devices are on the internet today. Example
of IPv4 10.1.1.0
IPv4
is grouped into four classes namely A, B, C, D and
E. although only the A,B and
C are in use. The class E
addresses are used for multicast
and E for research
and experiments. As I already
mentioned that IPv4 is a 32bit addressing system. This 32bit is
divided into 4
groups namely octet. An octet consist of 8bits
each. 8*4=32.
Transmission
- Unicast, multicast and broadcast. A unicast is one on one transmission. Take for example you called your sweetheart on phone. That’s a good example of unicast.
- Multicast can be like this, when you isolate some people from a group and communicate with them, for example when you decided to send particular message to your male friends only on whatsApp isolating the females.
- Broadcast is when you send message to all your whatsApp contacts. Meaning broadcast is for all.
Class A
The
class A addressing system uses the first bit as a network address and
other bits for the host. Meaning all the bits in the first octet are
turned on. Bits can be turn on by using 1s in all the bits.
Don't forget bits are only 1 and 0. when it is 1 its turned on and 0
is off respectively. Meaning
this class of address contains less networks and more host. The class
A address uses 8bits for network address and 24bits for host.
According to the creators of
the this addressing system, the first bit must be turned off. Meaning
the 8bits will be represented as 01111111 and not 1111111. which make
the network total to be 128 starting from 0. Meaning
the total
number of networks are between
0 to 127 networks. Mind
you 127 is already a reserved loopback
address which cannot be used.
Its reserved for diagnosis. Literary class A address consist of 126
valid network addresses. It
again contains 2^24-2 as the
number of hosts. Why minus 2?
the first and the last
addresses are not usable! The first number
cant
be used because its regarded as the network address and the last
address
which is regarded as the broadcast address. Example
of class A address: 10.8.8.10 the network address here is 10.0.0.0,
the host carries the 8.8.10. This
addressing can again be represented as network.host.host.host.
Class
B
The class B addressing system uses
the first two bytes or octet
as network address and the
other two bytes as host
addresses. The addressing
system designers again stole the 0 and 1 bits making the total number
of addresses here to 2^14, while
the host network is 2^16-2 respectively. The network address starts
from 128 up to 191. Example
of class B address: 136.12.8.5 the network address here is
136.12.0.0, while the host carries 8.5. It can be represented as
network.network.host.host.
Class
C
The
class C addressing system uses the first three bytes as the network
address and the remaining one for
host. The
addressing designers as normal removed some bits from the
network portion of the addressing system, here they remove 3, the
class C address normally starts with 110 that is why the 3 addresses
are removed, one bit each from each byte/octet. The network portion
becomes 24-3=21 that is the remaining addresses left. To calculate
the total number of network 2^21. The total number of hosts is 2^8-2.
it
can be represented as network.network.network.host.
Each
address class is again divided in two namely global and private
addresses. The global
addresses can be routed on the internet while the private ones cant
be routed on the internet. The global IP addresses are addresses
that one have to apply from organizations to get them. Certain
protocols have to be met before you can get global address, once
acquired no one on earth can be given that address again. IP
addresses must be unique in every network. Private IP
addresses are the addresses we can used within our private networks.
This addresses cant go online ie, they
cant be routed on the internet. Take for example when setting up a
local LAN in your house, you have apply for IP address that will be
disturbing and wastage of time. So the idea of private ip addressing
come with that solution. You can use the private address at any
moment without any restriction. Each address class has its own
private address.
Class
A Private Address 10.0.0.0 to
10.255.255.255
Class
B Private Address 172.16.0.0 to 172.31.255.255
Class
C Private Address 192.168.0.0 to 192.168.255.255
Broadcast
Address
This
is the address in which if it receive a packet, all devices within
the network will get that packet.
Its the last address on the
network. The broadcast is very important, host uses it to announce it
self to other devices on the network. Generically
in broadcast address all the bits are turned on ie.
11111111.11111111.11111111.11111111 or 255.255.255.255.
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to
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