| Description | Physical topology information for the local port
(identified by cPtopoExtCdpLocalChassis and
cPtopoExtCdpLocalPort of this row) can be discovered
from CDP running on the local port, if it is CDP capable
or from CDP running on a proxy interface. In the case of
optical ports running wavelength division multiplexing,
the physical connector port on which the CDP packet is
transmitted is different from the logical interface
representing the wavelength on which CDP is running. In
such a case, physical topology for the 'external' optical
port can be learned from CDP running on one of the
wavelengths.
This object is set to zero if physical topology information
for the local port is discovered from CDP running on itself.
Otherwise, this object contains the ifIndex value of the CDP
capable interface which is being used as proxy to learn
physical topology information for the local port.
Usage of this object is possible only if the local port
is the 'External Port', as specified in the CDP protocol,
for the proxy interface.
This object may be modified when the associated
cPtopoExtCdpRowStatus object has a value of 'active'. |