3Com S7906E - Switch, Configuration Manual

Page: 580 / 2621

1-3
Figure 1-1 A sample routing table
Router A
Router B
Router H
Router E
16.0.0.2
17.0.0.3
15.0.0.0
12.0.0.0
17.0.0.0
11.0.0.0 16.0.0.0
13.0.0.0
14.0.0.0
Router C
Router D
Router F
Router G
11.0.0.1
12.0.0.1
12.0.0.2
15.0.0.1
15.0.0.2
17.0.0.1
16.0.0.1
13.0.0.1
13.0.0.2
14.0.0.1
14.0.0.2
14.0.0.3
14.0.0.4
17.0.0.2
11.0.0.2
13.0.0.3
Destination Network Nexthop Interface
11.0.0.0 11.0.0.1 2
12.0.0.0 12.0.0.1 1
13.0.0.0 12.0.0.2 1
14.0.0.0 14.0.0.4 3
15.0.0.0 14.0.0.2 3
16.0.0.0 14.0.0.2 3
17.0.0.0 11.0.0.2 2
Routing Protocol Overview
Static Routing and Dynamic Routing
Static routing is easy to configure and requires less system resources. It works well in small, stable
networks with simple topologies. Its major drawback is that you must perform routing configuration
again whenever the network topology changes; it cannot adjust to network changes by itself.
Dynamic routing is based on dynamic routing protocols, which can detect network topology changes
and recalculate the routes accordingly. Therefore, dynamic routing is suitable for large networks. Its
disadvantages are that it is difficult to configure, and that it not only imposes higher requirements on the
system, but also consumes a certain amount of network resources.
Classification of Dynamic Routing Protocols
Dynamic routing protocols can be classified based on the following standards:
Operational scope
z
Interior gateway protocols (IGPs): Work within an autonomous system, including RIP, OSPF, and
IS-IS.