Specifies the precedence of a reachable address type.
When there are multiple reachable address types associated
with the longest match reachable address prefix, the route
selection algorithm first attempts to find routes to
reachable address types of greatest precedence. Among
routes to the same longest match reachable address prefix
with the same reachable address type, routes with the
least total administrative weight are preferred.
Smaller values take precedence over larger values. Local
internal reachable addresses, whether learned through ILMI
or as static routes, are given the highest priority
(i.e. 1).