What is stub in OSPF?
A stub area is an area in which you do not allow advertisements of external routes, which thus reduces the size of the database even more. Instead, a default summary route (0.0. Stub areas are shielded from external routes but receive information about networks that belong to other areas of the same OSPF domain.
What is NSSA in OSPF?
The OSPFv2 not-so-stubby area (NSSA) enables you to configure OSPFv2 areas that provide the benefits of stub areas, but that also are capable of importing external route information. This example shows two routing domains, a BGP domain and an OSPF domain. …
When to use stub / NSSA / totally NSSA In OSPF?
OSPF Areas are used mostly for filtering Routes between ABRs – ASBRs. In an Area, filtering is disabled (Type 1-2 LSAs are allowed only). Difference between NSSA/Totally NSSA and Stubby/Totally Areas is; NSSAs redistribute external routes (Type-7 LSA) into the Area., Stubbys don’t.
What are the different types of OSPF stub areas?
OSPF has special area types called stub areas: 1 Stub 2 Totally Stubby 3 Not-So-Stubby Area (NSSA) 4 Totally Not So Stubby Area (Totally NSSA) More
What’s the difference between NSSA and stubby areas?
Difference between NSSA/Totally NSSA and Stubby/Totally Areas is; NSSAs redistribute external routes (Type-7 LSA) into the Area., Stubbys don’t. NSSA was created because Stubby areas block all Type-5 external LSAs. So Stubby Area can not learn any external LSAs.
How is NSSA boundary router propagated into OSPF?
An NSSA autonomous system boundary router (ASBR) generates this LSA and an NSSA area border router (ABR) translates it into a type 5 LSA, which gets propagated into the OSPF domain. The network diagram demonstrates this principle. Refer to this network diagram as you use this document: In the network diagram, Area 1 is defined as a stub area.