def _get_default_metric(self):
return self.__default_metric<EOL>
Getter method for default_metric, mapped from YANG variable /network_instances/network_instance/protocols/protocol/isis/levels/level/link_state_database/lsp/tlvs/tlv/ipv4_external_reachability/prefixes/prefixes/default_metric/state/default_metric (oc-isis-types:narrow-metric)

    YANG Description: ISIS default metric value. This is a metric understood by every
Intermediate system in the domain. Each circuit shall have a
positive  integral value assigned for this metric. The value may be
associated with any  objective function of the circuit, but by
convention is intended to measure the capacity of the circuit for
handling traffic, for example, its throughput in  bits-per-second.
Higher values indicate a lower capacity.