Page 146 - Handout Computer Network.

• Shortest path first (SPF) algorithm—A calculation performed on the database
resulting in the SPF tree

• Routing table—A list of the known paths and interfaces. Engineers have
implemented this link-state concept in Open Shortest Path First (OSPF) routing.
RFC 1583 contains a description of OSPF link-state concepts and operations.
Figure 6-17 illustrates these link-state concepts.

Figure 6-17 shown a Link-State Concepts

6.7.2.1 Network Discovery Processes for Link-State Routing

LSAs are exchanged between routers, starting with directly connected networks.

Each router, in parallel with others, constructs a topological database consisting of all the
exchanged LSAs.
The SPF algorithm computes network accessibility.

The router constructs this logical topology as a tree, with itself as the root, consisting of
all possible paths to each network in the link-state protocol internetwork. It then sorts these
paths using SPF.

The router lists the best paths and the interfaces to these destination networks in the
routing table.
The router also maintains other databases of topology elements and status
details.

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