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Why are all areas connected to an area 0 backbone in OSPF?
In OSPF domains the area topology is restricted so that there must be a backbone area (area 0) and all other areas must have either physical or virtual connections to the backbone.
Why is OSPF vulnerable to a routing loop?
Because inter-area OSPF is distance vector, it is vulnerable to routing loops. It avoids loops by mandating a loop-free inter-area topology, in which traffic from one area can only reach another area through area 0. of the OSPF protocol.Pls do it in labs so that it can clarify the various behaviour of OSPF.
Which is an ABR for R5 in OSPF?
R5 is member of area 3 and it has a direct connection to R3 that is a valid ABR and injects into area 3 summary LSAs for all existing areas: 0,4,5, For this reason R5 has routes for links between R1 and R2. You can visualize the OSPF multi-area rules as a daisy flower with area 0 that is the center of the flower and the other areas are the petals.
How are inter-area networks dealt with in OSPF?
In OSPF, even though inter-area networks are effectively dealt with in a distance-vector style, they are nevertheless imported into an area in the form of LSA-3. An LSA-3 may reach the router through any of its interfaces in this area and this does not make a difference.
What is the purpose of OSPF in multiarea?
OSPF uses areas to simplify administration and optimize traffic and resource utilization. An area is simply a logical grouping of contiguous networks and routers. All routers in the same area have the same topology table and don’t know about routers in the other areas.
How to determine the cause of OSPF behavior?
In order to determine the cause of this behavior, here is the R4 show ip ospf border-routers command output (the cost on the R4 Interface Ethernet 0/2 is still set to 100): On R4, you can see that there are two Area Border Routers (ABRs) (0.0.0.2, which is R2, and 0.0.0.3, which is R3) and that R2 is the ASBR.
What do area IDs mean in OSPF network?
OSPF areas explained. Each area in an OSPF network must be connected to the backbone area (also known as area 0). All routers inside an area must have the same area ID in order to become OSPF neighbors. A router that has interfaces in more than one area (area 0 and area 1, for example) is known as an Area Border Router (ABR).