Routing Protocols And The Preferences Of The Discovered Routes; Supporting Load Balancing And Route Backup - H3C SecPath F1800-A Operation Manual

Operation Manual - Network and Routing Protocol
H3C SecPath F1800-A Firewall

2.2.1 Routing Protocols and the Preferences of the Discovered Routes

Different routing protocols (as well as the static configuration) may discover different
routes to the same destination, but not all these routes are optimal. In fact, at a certain
moment, only one routing protocol can determine the current route to a specific
destination. Thus, each of these routing protocols (including the static configuration)
is set with a preference. As a result, when there are multiple routing information
sources, the route discovered by the routing protocol with the higher preference will
become the current route. Routing protocols and the default preferences (the smaller
the value, the higher the preference is) of the routes discovered by them are shown in
Table 2-1.
Table 2-1 Routing protocols and the default preferences for the routes learned by
them
Routing protocol or route type
DIRECT
OSPF
IS-IS
STATIC
RIP
OSPF ASE
OSPF NSSA
IBGP
EBGP
UNKNOWN
In Table 2-1, 0 refers to a direct route. 255 refers to any route from unreliable source.
Except for direct routing and BGP (IBGP and EBGP), the preference of each dynamic
routing protocol can be manually configured at the request of users. In addition, the
preference of each static route can vary from each other.

2.2.2 Supporting Load Balancing and Route Backup

Load balancing
It supports multi-route mode; that is, you can configure several routes with the same
privilege to the same destination. All these routes will be adopted in turn for sending
IP packets to the destination if there is no route with higher privilege. In this way, the
network load balancing is achieved.
Chapter 2 IP Routing Protocol Overview
The preference of the route
0
10
15
60
100
150
150
256
256
255
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