What is an IP Address (Part2)

why the IP address starts with 192.168 and some times 10.10
what is the private IP address pool
what is the public IP address pool



 
IP address classes
Class
Range of
first octet
Format
Default subnet mask
Number of networks
Number of addresses per network  (hosts)
A
1-126
N.H.H.H
255.0.0.0
27 = 128
224 = 16777216
B
128-191
N.N.H.H
255.255.0.0
214 = 16384
216 = 65536
C
192-223
N.N.N.H
255.255.255.0
221 = 2097152
28 = 256
D
The addresses between 224 and 255




E




** N = Network portion (Network ID)
** H = Host portion (Host ID)

Class
Range of
first octet
Ranges of private networks
Uses
A
1-126
10.0.0.0 – 10.255.255.255
was designed only for very big networks
B
128-191
172.16.0.0-172.31.255.255
is best for medium sized networks
C
192-223
192.168.0.0-192.168.255.255
is best for smaller networks.
D
The addresses between 224 and 255

is used for multicast addresses
E

is used for scientific purposes

Note : all private IP address in class A,B or C will be located in these ranges because the rest of these ranges called public IP addresses which are owned by the IANA organization  (who sells this IPs to the ISP all over the world)

Each IP address has two components :-


1- Network ID - (N)
2- Host ID - (H)
 Ways to assign ip address to your device ( IP address assignment )

1-      DHCP
2-     
APIPA = 169.254.x.x  auto configuration range when a host can’t get an IP address from a DHCP server

3-     Static IP addresses :  manually assigned to a computer by the user


check what is the IP address?  (part1) to know more
see also DHCP
 
check this video to know your IP address