Traffic Sharing And Route Backup - H3C S7500 Series Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches
route. Routing protocols and their default route preferences (the smaller the value is,
the higher the preference is) are shown in
In the table, "0" is used for directly connected routes, and "255" is used for routes from
untrusted source.
Table 1-1 Routing protocols and corresponding route preferences
Routing protocol or type
DIRECT
OSPF
IS-IS
STATIC
RIP
OSPF ASE
OSPF NSSA
UNKNOWN
IBGP
EBGP
Except for direct routing, you can manually configure the preferences of various
dynamic routing protocols as required. In addition, you can configure different
preferences for different static routes.

1.2.2 Traffic Sharing and Route Backup

I. Traffic sharing
The S7500 series support multi-route mode, allowing the configuration of multiple
routes that reach the same destination and have the same preference. The same
destination can be reached via multiple different routes, whose preferences are equal.
When there is no route with a higher preference to the same destination, all these
routes will be adopted. Then, the packets destined for that same destination will be
forwarded through these routes in turn to implement traffic sharing.
II. Route backup
The S7500 series support route backup. When the primary route fails, the system
automatically switches to a backup route to improve network reliability.
To achieve route backup, you can configure multiple routes to the same destination
according to actual situation. One of these routes has the highest preference and is
called primary route. The other routes have descending preferences and are called
Chapter 1 IP Routing Protocol Overview
Table 1-1.
Preference of the corresponding route
0
10
15
60
100
150
150
255
256
256
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