Indicates the type of RIF to be retained in the RIF database.
shortestPath (2) is the RIF with the least number of hops. The
existing RIF will be replaced if the new RIF
is shorter.
quickestPath (3) is the 'first seen' RIF.
largestMTU (4) is the path that supports the largest frame as
indicated by the LF (largest frame bits) in the
routing control field (RCF).
lastSeen (5) is the 'most recently seen' RIF.
The default value for this object is device specific.