NLSR

Currently, Fib::removeOldNextHopsFromFibEntryAndNfd simply checks if the route exists in the routing table. If the route does not, it is removed from the prefix in NFD's FIB. Since NLSR limits the number of faces per prefix: a route can be installed, the routing table is later recalculated, a more optimal route is installed, and the previous route will not be removed since it is still a valid route in the routing table.

e.g

max-faces-per-prefix == 2

Before:

FIB
Name   NextHops
/a/b   (id=1, cost=0), (id=2, cost=25)

The routing table is recalculated and route (id=3, cost=10) is added

After:

FIB
Name   NextHops
/a/b   (id=1, cost=0), (id=3, cost=10), (id=2, cost=25)

This violates max-faces-per-prefix == 2