3Com Switch 7750 Configuration Guide

Routing Management Policy 283
The Switch 7750 Ethernet Switches (hereinafter referred to as the Switch 7750)
support the configuration of static routes as well as a series of dynamic routing
protocols such as RIP, OSPF and BGP. Moreover, the switches in operation can
automatically obtain some direct routes according to interface status and user
configuration.
Routing Management
Policy
On a Switch 7750, 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 by routing algorithm. On a
Switch 7750, 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.
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 endowed with
different preferences. When there are multiple routing information sources, the
route discovered by the routing protocol with the highest preference will become
the current route. Routing protocols and their default route preferences (the
smaller the value, the higher the preference is) are shown in Table 210.
In the table, “0” is used for directly connected routes, and “255” is used for
routes from untrusted source.
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
Table 210 Routing protocols and corresponding route preferences
Routing protocol or type Preference of the corresponding route
DIRECT 0
OSPF 10
IS-IS 15
STATIC 60
RIP 100
OSPF ASE 150
OSPF NSSA 150
UNKNOWN 255
IBGP 256
EBGP 256