Static or Dynamic routing?

Devilsbane

I know that dynamic routing is usually preferred because the amount of time that would be required to manually maintain routing tables would be through the roof. But I was always told that static tables would have a better performance due to the fact that they never needed to calculate which route to pick, it was set in stone.

Reading the MS press book today and, "Static and dynamic routing both provide the same level of router performance. The same information ends up in the routing table; the only difference is how it gets there."

So which way is correct?

Met44

Once the routes are in the routing table, there is no difference (as long as you don't manually enter the routes in such a way that a recursive lookup is required, or other silliness). To get the routes into the routing table in the first place, a dynamic routing protocol will incur oft-negligible network and processing overhead. As you say, this is only an issue in unusual circumstances.

The first source seems to refer to calculating which route to install in the routing table based on available information from neighbors/local configuration, whereas the second source seems to be talking about how to select a path based on information that's already in the routing table.

Bl8ckr0uter

Devilsbane wrote: »

Reading the MS press book today and, "Static and dynamic routing both provide the same level of router performance. The same information ends up in the routing table; the only difference is how it gets there."

So which way is correct?

I don't think this is true. When you do dynamic routing, additional processing power is needed to actually facilitate the demands of the protocol. Like OSPF and EIGRP all send out information on the wire to form neighbors, send routing tables, keep neighbors and etc. Static routing does not require such actions from the router.

Static Routing= More Secure, Less CPU intensive, more predictable
Dynamic Routing= Scablable,