aguilera
10-30-2007, 07:52 AM
OSPF can be deployed as an EGP. LSA type 9, 10 and 11 help exdend OSPF functionality and reach.
The flooding scope associated with each Opaque link-state type is
defined as follows.
o Link-state type-9 denotes a link-local scope. Type-9 Opaque
LSAs are not flooded beyond the local (sub)network.
o Link-state type-10 denotes an area-local scope. Type-10 Opaque
LSAs are not flooded beyond the borders of their associated area.
o Link-state type-11 denotes that the LSA is flooded throughout
the Autonomous System (AS). The flooding scope of type-11
LSAs are equivalent to the flooding scope of AS-external (type-5)
LSAs. Specifically, type-11 Opaque LSAs are 1) flooded
throughout all transit areas, 2) not flooded into stub areas or
NSSAs from the backbone and 3) not originated by routers into
their connected stub areas or NSSAs. As with type-5 LSAs, if a
type-11 Opaque LSA is received in a stub area or NSSA from a
neighboring router within the stub area or NSSA the LSA is
rejected.
The flooding scope associated with each Opaque link-state type is
defined as follows.
o Link-state type-9 denotes a link-local scope. Type-9 Opaque
LSAs are not flooded beyond the local (sub)network.
o Link-state type-10 denotes an area-local scope. Type-10 Opaque
LSAs are not flooded beyond the borders of their associated area.
o Link-state type-11 denotes that the LSA is flooded throughout
the Autonomous System (AS). The flooding scope of type-11
LSAs are equivalent to the flooding scope of AS-external (type-5)
LSAs. Specifically, type-11 Opaque LSAs are 1) flooded
throughout all transit areas, 2) not flooded into stub areas or
NSSAs from the backbone and 3) not originated by routers into
their connected stub areas or NSSAs. As with type-5 LSAs, if a
type-11 Opaque LSA is received in a stub area or NSSA from a
neighboring router within the stub area or NSSA the LSA is
rejected.