IPv6: Static atau Dynamic Routing

Static or Dynamic Routing?

When reading (or being lectured about) all the glorious details of dynamic routing protocols, it's hard not to come away with the impression that dynamic routing is always better than static routing. It's important to keep in mind that the primary duty of a dynamic routing protocol is to automatically detect and adapt to topological changes in the network. The price of this "automation" is paid in bandwidth and maybe queue space, in memory, and in processing time.

Another price of dynamic routing is a reduced control of routing choices. The routing protocol decides what the best path is to a given destination, you don't. If precise control of path selection is important, particularly when the path you want is different from the path a routing protocol would choose, static routing is a better choice.

A frequent objection to static routing is that it is hard to administer. This criticism might be true of medium to large topologies with many alternative routes, but it is certainly not true of small networks with few or no alternative routes.

The network in Figure 4-14 has a hub-and-spoke topology popular in smaller networks. If a spoke to any router breaks, is there another route for a dynamic routing protocol to choose? This network is an ideal candidate for static routing. Configure one static route in the hub router for each spoke router and a single default route in each spoke router pointing to the hub, and the network is ready to go. (Default routes are covered in Chapter 12, "Default Routes and On-Demand Routing.")

Figure 4-14. This hub-and-spoke network is ideal for static routing.When designing a network, the simplest solution is almost always the best solution. It is good practice to choose a dynamic routing protocol only after determining that static routing is not a practical solution for the design at hand.

Pranala Menarik

• IPv6: Advanced Routing