Telindus 1031, Руководство пользователя и справочник

Страница: 109 / 394

Telindus 1031 Router Chapter 7
User manual Configuring the router
99
Static versus dynamic routing
The following table states the differences between static and dynamic routing:
Routing algo-
rithm Description
static Static routing algorithms are hardly algorithms at all, but are table mappings estab-
lished by the network administrator before the beginning of routing. These map-
pings do not change unless the network administrator alters them. Static routing
algorithms work well in environments where network traffic is relatively predictable
and where network design is relatively simple.
dynamic Because static routing systems cannot react to network changes, they generally
are considered unsuitable for today's large, constantly changing networks. Most of
the dominant routing algorithms today are dynamic routing algorithms, which
adjust to changing network circumstances by analysing incoming routing update
messages. If the message indicates that a network change has occurred, the rout-
ing software recalculates routes and sends out new routing update messages.
These messages permeate the network, stimulating routers to rerun their algo-
rithms and change their routing tables accordingly.
Also refer to 7.3.1 - Introducing RIP on page 108 .
static and
dynamic Dynamic routing algorithms can be supplemented with static routes where appro-
priate. A router of last resort (a router to which all unroutable packets are sent), for
example, can be designated to act as a repository for all unroutable packets,
ensuring that all messages are at least handled in some way.