@staticmethod
def _get_mac_from_dn(dn):
    """
        Extract the MAC address from the dn

        :param dn: string containing the distinguished name URL
        :return: String containing the MAC address or None if not found
        """
    if '/stcep-' in dn:
        return str(dn.split('/stcep-')[1].partition('-type-')[0])
    if '/cep-' in dn:
        return str(dn.split('/cep-')[1].partition('/')[0])
    if '/epdef-' in dn:
        return str(dn.split('/cep-')[1].partition('/')[0])
    return None
