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TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP is today's most popular network protocol and is the protocol in the Internet. It is a routable protocol that provides connection between heterogeneous systems, these are the main reasons the protocol is so widely adapted; for example it allows communication between UNIX, Windows, Novell Netware and Mac OS computers spread over multiple interconnected networks. The "TCP/IP protocol" is actually the "TCP/IP suite" composed of many different protocols each with its own functions. The two main protocols are in its name: the Internet Protocol and the Transmission Control Protocol.

IP addressing is assigning a 32-bit logical numeric address to a network device. Every IP address on the network must be unique. An IP address is represented in a dotted decimal format, for example: 134.51.24.8. As you can see the address is divided in 4 parts, these parts are called octets. The current used addressing schema in IPV4 is divided in 5 Classes:

Address Class IP address range Default Subnet Mask Number of Networks Number of Hosts CIDR
Class A 1-126 255.0.0.0 126 16,777,214 /8
Class B
 128-191 255.255.0.0 16,384 65,534 /16
Class C 192-223 255.255.255.0 2,097,152 254 /24
Class D 224-239 Multicast n/a n/a n/a
Class E 240-255 Reserved n/a n/a n/a

In a class A network, the first octet defines the network portion of the address. The last three octets are used for host addresses and subnet masking.

Network.Host.Host.Host
255.0.0.0

In a class B network, the first two octets define the network portion of the address. The last two octets are used for host addresses and subnet masking.

Network.Network.Host.Host
255.255.0.0

In a class C network, the first three octets define the network portion of the address. The last octet is used for host addresses and subnet masking.

Network.Network.Network.Host
255.255.255.0

A private network is commonly known as an Intranet.

The Internet Assigned Numbers Authority (IANA) has set aside the following IP address range for Intranet networks.

Private IP Address
IANA reserved 4 address ranges to be used in private networks; these addresses won't appear on the Internet avoiding IP address conflicts

10.0.0.0 through 10.255.255.255
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255

Special Address

Loopback Address           127.0.0.1 (use for loopback testing)


Automatic Private IP Addressing
(APIPA) is a feature of Windows-based operating systems that enables a computer to automatically assign itself an IP address when there is no Dynamic Host Configuration Protocol (DHCP) server available to perform that function. APIPA serves as a DHCP server failover mechanism and makes it easier to configure and support small local area networks (LANs).

169.254.0.0 - 169.254.255.255

 

192

224

240

248

252

254

255

128 

64

32

16

8

4

2

1

I

I

I

I

I

I

I

I

Now take the remainder and convert that to decimal.  Here we have 4 left, so I I I I is:
8+4+2+1= 15.  You can use 15 IP addresses only, instead of the 255 normally allocated.

IPV6
IPV6 will be 128 bit and will use 8 sets of number and use Hexadecimal to look like some horrible number like:

3455:9FFD:5578:3444:2222:4444:3DCD:4FCD
Network Routing Prefix - Subnet ID - Interface ID