H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches Chapter 1 IP Routing Protocol Overview
1-3
Router A
Router B
Router H
Router E
16.0.0.2
17.0.0.2
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
11.0.0.2
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
13.0.0.3
14.0.0.1 14.0.0.3
15.0.0.3
14.0.0.2
14.0.0.4
Destination Network Nexthop Interface
11.0.0.0 14.0.0.1 3
12.0.0.0 14.0.0.1 3
13.0.0.0 16.0.0.1 2
14.0.0.0 14.0.0.3 3
15.0.0.0 17.0.0.2 1
16.0.0.0 16.0.0.2 2
17.0.0.0 17.0.0.1 1
Figure 1-1 Routing table
1.2 Routing Management Policy
On an S7500 switch, you can manually configure a static route to a certain destination,
or configure a dynamic routing protocol to make the switch interact with other routers
in the internetwork and find routes. On an S7500 switch, the static routes configured
by the user and the dynamic routes discovered by routing protocols are managed
uniformly. The static routes and the routes learned or configured by different routing
protocols can also be shared among routing protocols.
1.2.1 Routing Protocols and Preferences
Different routing protocols may discover different routes to the same destination, but
only one route among these routes and the static routes is optimal. In fact, at any
given moment, only one routing protocol can determine the current route to a specific
destination. Routing protocols (including static routing) are assigned different
preferences. When there are multiple routing information sources, the route
discovered by the routing protocol with the highest preference will become the current