import re


def is_ipv4(address):
    """ Checks if given address is valid IPv4 address

    :param str address: IP address to check
    :return bool: True if address is valid IPv4 address, False otherwise
    """

    regexp = "^(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
    if re.match(regexp, address):
        return True

    return False