retrieve subnet for given IP

geoip_subnet.go

package main

import (
	"net"
	"fmt"
)

// Get the subnet for a given IP address
func geoIP() {
	ip := net.ParseIP("128.174.5.59")
	ipv4Mask := net.CIDRMask(24, 32)
	fmt.Println(ip.Mask(ipv4Mask))
}