Private vs Public IP

   . IP Addresses are classified into two types namely Private IP and Public IP.
   . Public IP is valid address which can be used to access internet.
   . Private IP is used within network which is assigned to each device inside network.
   . Allocation of IP is done by IANA ( Internet Assigned Number Authority).

   Private IP:

       . Each device inside network contains a specific IP address.
       . These are assigned by router automatically.
       . They need not to be unique over world because they are not accessed directly.
       . It means various devices can have same Private IP across world i.e. outside private network.
       . It is not accessed over internet.
       . Referred as Internal IP Address.

   Classes of Private IP:

       . There are certain addresses in each class of IP Addresses.
       . They are reserved for private networks.
       . Any IP Address in the below Classes come under Private IP Address.
             Class A: to 
             Class B: to
             Class C: to 

   How to know Private IP?

       . Go to command prompt and type in ipconfig.

   Public IP:

       . It is globally unique IP address assigned by Internet Service Provider (ISP).
       . Each and every Private IP is accessed with internet by the help of Public IP Address.
       . NAT (Network Address Translator) is designed for IP Address conversation.
       . It allows router to act as an agent between internet and local network.
       . Referred as External IP Address.   

   How to know Public IP?

       . Type in 'What is my ip' in browser.
       . To know Public IP of any website, we can find it out by using command prompt.
       . Enter ping , it shows the Public IP Address of that particular site.


Private IPPublic IP
Used with LAN or within organizationUsed on public network (Internet)
Not recognized on internetRecognized on internet
Given by AdministratorGiven by Internet Service Provider by IANA
Unique within network or organizationGlobally unique
FreeHave to pay Service Provider
Unregistered IPRegistered IP