Contents
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.
How does OSPF area work?
Each OSPF router passes along information about the routes and costs they’ve heard about to all of their adjacent OSPF routers, called neighbors. OSPF routers rely on cost to compute the shortest path through the network between themselves and a remote router or network destination.
How many routers can be in an OSPF area?
Generally, an area should have no more than 50 routers. Areas that suffer with unstable links should be smaller. Number of areas supported by any one router: A router must run the link-state algorithm for each link-state change that occurs for every area in which the router resides.
What is OSPF area, OSPF hierarchical network design?
Open Shortest Path First (OSPF) allows the network to be designed in two layer hierarchies. Area 0 at one layer and all other Areas at other layer. An Open Shortest Path First (OSPF) Area must be configured as a group of contiguous IP networks. This allows Route Summerization at Area level.
Which is the best number for an OSPF design?
As mentioned in the preceding note, 50 or fewer routers is the most optimal design. This number is intended as an appropriate indication that an OSPF design is unsatisfactory and should be reconsidered, focusing on a smaller area 0.
What should be considered in determining OSPF area placement?
Geographic and functional boundaries should be considered in determining OSPF area placement. As discussed previously, to improve performance minimize the routing information advertised into and out of areas. Bear in mind that anything in the LSA database must be propagated to all routers within the area.
How to design a scalable OSPF route summarization?
This number is intended as an appropriate indication that an OSPF design is unsatisfactory and should be reconsidered, focusing on a smaller area 0. OSPF requires two levels of hierarchy in your network, as shown in Figure 3-13. Route summarization is extremely desirable for a reliable and scalable OSPF network.