Type of RIF to cache. When the explorer option (1) is selected
the existing RIF may be replaced only if the received frame is
an explorer. When the 'all' option (2) is selected the existing
RIF may be replaced for any SR frame received with a valid RIF.
Some devices will use this in conjunction with the
ctTransRifDbWeightState option to determine which RIFs may be
cached.
The default for this object is product specific.