cisco book 350-401

cisco book 350-401.. It uses Link State Announcements (LSA) to propagate triggered incremental updates and hence convergence is fast.. It is a classless protocol that can use a hierarchical design supporting VLSM and route summarization, which reduces routing overhead. . It uses a hierarchical structure containing two layers to confine the problem to the area and reduce routing overhead.. It uses a metric (overhead) that is inversely proportional to the bandwidth of the interface o . It gives you full control over routing update information through aggregation and filtering. However. the OSPF also has some disadvantages as follows.. It requires more memory to store the adjacency table (OSPF neighbor list), topology table (link state database containing all routers and their routes/links), and routing table.. It requires additional CPU cycles to perform the SPF algorithm, and when OSPF is first enabled on a router, it needs to build the adjacency table and topologyThis is especially true when pouncing on a watch. . For large networks. the network must be carefully designed to divide the routers into different areas and thus divide the network into a reasonable hierarchy. . It is more complex to configure and more difficult to troubleshoot than distance vectoring protocols.Exam points to keep in mind Advantages and disadvantages of OSPF: It is an open standard that supports a hierarchical design using areas that will openWhen choosing a routing protocol, it is helpful to know the advantages and disadvantages of various routing protocols. OSPF is typically used in large enterprise networks that use a mix of routers from multiple vendors or whose policies require the use of open standards-based routing protocols, which gives companies options when replacing established routers.Practical experience typically suggests that Cisco recommends using a higher-level routing protocol such as OSPF or EIGRP when there are more than 50 routers in the network. o In environments where multi-vendor routers are used, there is essentially no choice but to use OSPF.Chapter 19 OSPF Routing 497