OSPF NSSA ABR advertises default route

In an NSSA OSPF topology, the following command will generate a Type 7 default route:

router ospf 1 area 1 nssa default-information-originate

The following rules apply:

  • When applied to an NSSA ASBR, this will only generate a default route if:
    • there is a valid default route in the routing table that has been learned through a non-OSPF protocol.
    • the keyword always is added at the end of the command.
  • When applied to an NSSA ABR, this will generate a default route with or without a valid default route in the routing table.





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