CIDR conflicts checker

cidr.go

package main

import (
	"fmt"
	"net"
)

func CIDRConflict(cidr1, cidr2 string) (bool, error) {
	_, network1, err := net.ParseCIDR(cidr1)
	if err != nil {
		return false, err
	}

	_, network2, err := net.ParseCIDR(cidr2)
	if err != nil {
		return false, err
	}

	return intersect(network1, network2), nil
}

func intersect(n1, n2 *net.IPNet) bool {
	return n2.Contains(n1.IP) || n1.Contains(n2.IP)
}

func main() {
	cidr1 := "100.64.0.0/16"
	cidr2 := "100.128.0.0/16"

	conflict, err := CIDRConflict(cidr1, cidr2)
	if err != nil {
		fmt.Printf("Error: %v\n", err)
		return
	}

	if conflict {
		fmt.Printf("CIDR blocks %s and %s conflict.\n", cidr1, cidr2)
	} else {
		fmt.Printf("CIDR blocks %s and %s do NOT conflict.\n", cidr1, cidr2)
	}
}