Golang : Convert IP version 6 address to integer or decimal number

Problem :

You have IP address version 6 in string format and you want to convert it into integer. How to do that?

NOTE : IP address in decimal number format is easier to search, filter or compare. For example, searching for IP address in a given range.

Solution :

Use math/big.Int.SetBytes() to convert the IPv6 address to a signed multi-precision integer.

 package main

 import (
 "fmt"
 "math/big"
 "net"
 )

 func IP6toInt(IPv6Address net.IP) *big.Int {
 IPv6Int := big.NewInt(0)

 // from http://golang.org/pkg/net/#pkg-constants
 // IPv6len = 16
 IPv6Int.SetBytes(IPv6Address.To16())  
 return IPv6Int
 }

 func main() {

 ipv6Decimal := IP6toInt(net.ParseIP("FE80::0202:B3FF:FE1E:8329"))
 fmt.Println(ipv6Decimal)
 }

Output :

338288524927261089654163772891438416681

References :

https://golang.org/pkg/math/big/#Int.SetBytes

http://stackoverflow.com/questions/23297141/golang-net-ip-to-ipv6-from-mysql-as-decimal39-0-conversion