def ip2num(ip):#ip to int num

    lp = [int(x) for x in ip.split('.')]

    return lp[0] << 24 | lp[1] << 16 | lp[2] << 8 | lp[3]

def num2ip(num):# int num to ip

    ip = ['', '', '', '']

    ip[3] = (num & 0xff)

    ip[2] = (num & 0xff00) >> 8

    ip[1] = (num & 0xff0000) >> 16

    ip[0] = (num & 0xff000000) >> 24

    return '%s.%s.%s.%s' % (ip[0], ip[1], ip[2], ip[3])

def iprange(ip1,ip2):

    # print ip1,ip2

    # return ip1, ip2, 3

    num1 = ip2num(ip1)

    num2 = ip2num(ip2)

    tmp = num2 - num1

    if tmp < 0:

        return None

    else:

        return num1, num2, tmp