Why do we need stub area?
To control the advertisement of external routes into an area, OSPF uses stub areas. By designating an area border router (ABR) interface to the area as a stub interface, you suppress external route advertisements through the ABR.
What is the difference between backbone area and stub area in OSPF?
The backbone is considered a standard area. Stub areas can contain type 1, 2, and 3 LSAs. A default route is substituted for external routes. Totally stubby areas can only contain type 1 and 2 LSAs, and a single type 3 LSA.
What is the difference between stub and totally stubby area?
A stub area is an area in which advertisements of external routes are not allowed, reducing the size of the database. A totally stubby area (TSA) is a stub area in which summary link-state advertisement (type 3 LSAs) are not sent. A default summary LSA, with a prefix of 0.0.
What is stub area in CCNA?
Stub Area is the area that do not accept the External LSAs(Type 5). Stub Areas accept the summary LSAs Type 3 beside the Default Route from the Backbone Area. They also do not accept Type 4 LSAs.
What is OSPF area?
By definition an OSPF area is a collection of networks, not a collection of routers. A backbone network segment is an IP subnet that belongs to the area identified by 0.0. 0.0. Areas that are not physically connected to the backbone are logically connected by a backbone ABR using an OSPF virtual link.
What does OSPF area contain?
Explanation: An OSPF area contains one set of link-state information, although each router within the area will process that information individually to form its own SPF tree. OSPF process IDs are locally significant and are created by the administrator.
Why We Use Area in OSPF?
In OSPF, a single autonomous system (AS) can be divided into smaller groups called areas. This reduces the number of link-state advertisements (LSAs) and other OSPF overhead traffic sent on the network, and it reduces the size of the topology database that each router must maintain.
Why do we need AREA 0 in OSPF?
Area 0 was chosen to be the backbone, the number 0 or 0.0. 0.0 is just a number. Because OSPF is link state the LSDB must be identical within an area. This is to ensure that the SPF calculation is consistent and to prevent routing loops.
Why do we use OSPF areas?
What is OSPF area range?
The area range command is used only with area border routers (ABRs). It is used to consolidate or summarize routes for an area. The result is that a single summary route is advertised to other areas by the ABR. Routing information is condensed at area boundaries.
What is a stub area?
Stub area, also called stub area, the so-called stub area, means that the area does not accept any external routes of non-OSPF network, if it wants to reach those external routes, only Need to send it through the default route. This area supports 1, 2, and 3 LSAs.