what is IP Address

IP Address

IP address is logical address or numerical identification of a computer.

IP version 4

It is 32 bit address in the decimal format with 4 octets. It has 2 parts-Network ID and Host ID

Network ID tell the number of network bits or tell that computer belong to which network.

Host ID tell the number of hosts per network or tell the unique identify of a computer in particular network.

Subnet Mask is  a number which can differentiate between network ID and host ID or it can tell the number of network bits. We can also use Network Prefix instead of Subnet Mask like   /8   instead of  255.0.0.0

IP address range is 0 to 255

There are 4 octets   W.X.Y.Z

Minimum Value of IP address is    0.0.0.0

Maximum value of IP address is     255.255.255.255

Octet means 8 bits   and each bit has some value like

          1        1         1         1          1        1      1     1

   128       64      32      16        8       4        2     1

                   128+64+32+16+8+4+2+1 = 255

NOTE: We can convert Binary into Decimal and vice-versa

There are different classes of IP address:

Class                          Range of W (W.X.Y.Z)

  A                              1-126

  B                              128-191                                                       

  C                             192-223

  D                              224-239                   

  E                               240-254         

 

0 is for LAN card

255 is broadcast address

127 is Loopback address use for network troubleshooting

                                                             

Class A, B, C (1-223) use for general purpose

Class D (224-239) or 224.0.0.0 to 239.255.255.255 use for multicasting purpose

Class E (240-247) reserve for future purpose

Class E (248-254) use by NASA (National Aeronautics and Space Administration)

Class       Range     Network ID        Host ID         Subnet Mask          No. of host per network

 A             1-126          W                     X.Y.Z           /8       255.0.0.0               2²⁴ - 2 =   16,777,214

 

B         128-191         W.X                       Y.Z          /16 255.255.0.0              2¹⁶ - 2   =       65,534

 C         192-223         W.X.Y                       Z          /24 255.255.255.0           2⁸ - 2    =           254

Types of IP address

1. Public IP    They are use to connect Internet directly and has to be            register by InterNIC. Except Private IP and Special IP, all are Public IP.

2. Private IP   They are use within private network (LAN and Intranet). They are use to save Public IP, to manage IP addressing etc. Range is fix for private IP:

           

                        Class A Private IP          10.0.0.1   to   10.255.255.254

                        Class B Private IP         172.16.0.1 to 172.31.255.254

                        Class C Private IP       192.168.1.1 to 192.168.255.254

3. Special IP   They are also use within private network but they are use only for special purpose

            (i) Loopback address                                              -> Any IP starting with 127.0.0.1

            (ii) ICS (Internet Connection Sharing)               -> 192.168.0.1 to 192.168.0.254

            (iii)APIPA                                                                   -> 169.254.0.1 to 169.254.255.254