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Chapter (3) Networking Media and Data Link Layers Protocols
An administrator also can statically assign these directions to the router.
6.5.2 Static Versus Dynamic Routes
Static route knowledge is administered manually by a network administrator who enters
it into a router’s configuration. The administrator must update this static route entry manually
whenever an internetwork topology change requires an update. Dynamic route knowledge
works differently. After a network administrator enters configuration commands to start
dynamic routing, the route knowledge automatically is updated by a routing process whenever
new information is received from the internetwork.
Changes in dynamic knowledge are exchanged between routers as part of the update
process.
6.5.3 The Purpose of a Static Route
Static routing has several useful applications. Dynamic routing tends to reveal
everything known about an internetwork; for security reasons, however, you might want to
hide parts of an internetwork. Static routing enables you to specify the information that you
want to reveal about restricted networks. When a network is accessible by only one path, a
static route to the network can be sufficient. This type of network is called a stub network.
A stub network is an OSPF area that carries a default route, intra-area routes, and
interarea routes, but that does not carry external routes. Configuring static routing to a stub
network avoids the overhead of dynamic routing, as shown in Figure 6-9 shown a Static Route
Operation.
Figure 6 - 9 shown a Static Route Operation
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