@classmethod
def _parseDn2PortId(cls, dn):
    """
        This will parse the dn and return a port_id string.

        Handles DNs that look like the following:
        topology/pod-1/node-103/sys/phys-[eth1/12]
        and returns 1/103/1/12.
        """
    name = dn.split('/')
    pod = name[1].split('-')[1]
    node = name[2].split('-')[1]
    module = name[4].split('[')[1]
    interface_type = module[:3]
    module = module[3:]
    port = name[5].split(']')[0]
    return '{0}/{1}/{2}/{3}'.format(pod, node, module, port)
