Purchasing IP Blocks

   Why IP?

        . Every device connected to internet should have an identifier called IP Address.
        . With the help of these IP Addresses, users communicate with each other over the world.
        . IPs are of two types IPv4 and IPv6 which differ in supporting number of address spaces it can provide.
        . IPv4 supports 4.3 billion address spaces and Ipv6 supports plenty of addresses which are sufficient for future use.

   Who provides IP Address?   

        . Users are assigned IP Addresses by Internet Service Providers (ISP).
        . ISPs obtain allocations of IP addresses from Local Internet Registry (LIR) or National Internet Registry (NIR) or Regional Internet Registry (RIR).
        . Internet Assigned Numbers Authority (IANA) globally coordinates the IP Addressing System.
        . IANA assigns blocks of IP to the RIR which is of 5 regions which is managed by Internet Corporation for Assigned Numbers and Names (ICANN).
RIRAbbreviationAreas covered
AFRICAfrican Network Information CenterAfrican region
APNICAsia and Pacific Network Information CenterAsia, Australia, New Zealand and neighbouring countries
ARINAmerican Registry for Internet NumbersCanada, USA, Caribbean region
LACNICLatin America and Caribbean Network Information CenterLatin America, Caribbean region
RIPE NCCReseaux IP European Network Coordination CenterEurope, Middle East, Central Asia
        . RIR assigns IP address to the next level NIR.
        . NIR assigns IP addresses to LIR and also to the ISPs and end users directly.
        . Hierarchy of assignment of IP numbers is as shown below:

    Purchasing IP blocks:

        . When we wanted to purchase IP blocks, we need to contact the RIR as per our region.
        . IP addresses are assigned to networks in different sizes of blocks. 
        . Size of block is written after oblique (/), which shows number of IPs contained in that block.
        . Example: If ISP assigned /24, they would receive 32-24=8=>2^8 (256) addresses.
        . By contacting to particular RIR eg APNIC, we can follow further steps to purchase IP block.

             . Requesting for IP address from LACNIC: Type in "ip request for lacnic" in browser.