'Delete flow for fdb
This method is assumed to be used by method fdb_remove_tun.
We expect to delete a flow entry to send a packet to specified port
from bridge.
And you may delete some information for local arp response.
:param br: represent the bridge on which del_fdb_flow should be
applied.
:param port_info: PortInfo instance to include mac and ip.
.mac_address
.ip_address
:remote_ip: remote ip address.
:param lvm: local VLAN map of a network. See add_fdb_flow for
more explanation.
:param ofport: a port to delete.'

@abc.abstractmethod
def del_fdb_flow(self, br, port_info, remote_ip, lvm, ofport):

    pass
