Ospf will only put multiple routes in table if the metrics are equal , its not like bgp where there are multiple paths installed and based on a preferred route and you can still view the less preferred , ospf will only add the best route or equal routes that match exactly in cost
if the path from r1 - r5 is equal in cost over r2 and r4 you should see 2 routes but if if one is gig and the other fast Ethernet the gig will be put in the table , I don't think there is a way to see the routes that it decides not to put in the table after it calculates the best path if I understood you correctly probably because its link state and everyone knows what each other knows it may be a resource issue why its not viewable lsdb can get very large in certain networks having multiple routes that are not required in the table , more information that has to be shared and processed
OSPF-running routers use these criteria to select the best route to be installed in the routing table:
| A) |
When there are multiple routes available to the same network with different route types, routers use this order of preference (from highest to lowest): 1. Intra-area routes. 2. Inter-area routes. 3. External Type-1 routes. 4. External Type-2 routes. |
| B) |
If there are multiple routes to a network with the same route type, the OSPF metric calculated as cost based on the bandwidth is used for selecting the best route. The route with the lowest value for cost is chosen as the best route. |
| C) |
If there are multiple routes to a network with the same route type and cost, it chooses all the routes to be installed in the routing table, and the router does equal cost load balancing across multiple paths. |
