IP Blocks

The two most common versions of IP we use today is IPv4 and IPv6. Both come with finite pool of numbers.

• Not every IP address in the pool can be assigned to the machines and devices. Some reserved for other users, such as for use in private networks.
• So the total number of IP address available for allocation is less than the total number in the pool.

IP address are assigned to network in different sizes called 'blocks'.

• The size of block is assigned is written after the oblique('/'), which shows the number of IP address contained in that block.
• The size of the bits written after the oblique is called Slash notation.
• The lower the number after the oblique the more address contained in that block.

  

For example, if an ISP is assigned a '/24' as 192.0.2.0/24 it provides 32-24 = 8 i.e 2^8 = 256 IP address in IPv4 version.

IPv6 is similar to IPv4 but it is structured so that all LANs have 64 bit network.

• If a '/24' IPv6 allocation is made it would make 16,777,216 /48 or 4,294,967,296 /56 assignments.

Purchase IP blocks :

There are many reasons that a person or company will need their own IP address block.

• You can keep that IP address or block of IP address as you move from one ISP to another ISP.
• IP address are purchased in blocks by the organisations with lot of money.
• Need to get an IP address or block of IP address assigned from your Regional Internet Registry(RIR).

If you need to have your own IP address you will need contact one of the five RIRs.

• American Registry for Internet Numbers(ARIN) for US, Canada, some parts of Caribbean region.
• Africa Network Information Center(AFRINIC) for Africa.
• Asia Pacific Network Information center(APNIC) for Asia, Australia, NZ and neighboring countries.
• Latin America and Caribbean Network Information center(LACNIC) for parts of Caribbean region.
• Reseaux IP Europeans Network Coordination Center(RIPE NCC) for Europe, Russia and Central Asia.

Cost for different blocks of sizes.

• Block size smaller than /20 is $1,250.
• Block size /20 or /19 is $2,250.
• Block size between /19 - /16 is $4,500.
• Block size between /16 - /14 is $9,000.
• Block size larger than /14 is $18,000.