The value of vRtrRipAdvertisedRouteTimerRemaining gives the
number of seconds till the flush timer expires. The flush
timer is active for only those routes which are no longer
valid. Such routes will be advertised with a metric of 16
till the flush timer expires after which they will be removed
from the database.
vRtrRipAdvertisedRouteTimerRemaining will have a value of -1
for valid routes for which the flush timer is not active.