Convert an IP address to an IP Number

By Vikas Bagwe -
IP address (IPv4 / IPv6) is divided into 4 sub-blocks. Each sub-block has a different weight number each powered by 256.

IP number is being used in the database because it is efficient to search between a range of number in database.

Beginning IP number and Ending IP Number are calculated based on following formula: IP Number = 16777216*w + 65536*x + 256*y + z

(Formula 1) where IP Address = w.x.y.z

For example, if IP address is "202.186.13.4", then its IP Number "3401190660" is based on the Formula 1.

IP Address = 202.186.13.4

So, w = 202, x = 186, y = 13 and z = 4

IP Number = 16777216*202 + 65536*186 + 256*13 + 4

= 3388997632 + 12189696 + 3328 + 4 = 3401190660

To reverse IP number to IP address,

w = int ( IP Number / 16777216 ) % 256

x = int ( IP Number / 65536 ) % 256

y = int ( IP Number / 256 ) % 256

z = int ( IP Number ) % 256

IP Address = w.x.y.z

where % is the mod operator and int is return the integer part of the division.
In Microsoft Excel you can easily find out computation of  above formula for calculating answer of w by typing formula =MOD(int ( IP Number / 16777216 ),256) same method is applicable for x,y & z.

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