H3C Technologies H3C S12500 Series Switches - Manual (Page 19)

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Table 3 Route types and default route preferences
Routing type Preference
Direct route 0
OSPF 10
IS-IS 15
Static route 60
RIP 100
OSPF ASE 150
OSPF NSSA 150
IBGP 255
EBGP 255
Unknown (route from an untrusted source) 256
Configuring the maximum number of ECMP routes
A routing protocol might find multiple optimal equal-cost routes to the same destination. You can use
these routes to implement equal-cost multi-path (ECMP) load sharing.
To configure the maximum number of ECMP routes:
Step Command Remarks
1. Enter system view. system-view N/A
2. Configure the maximum
number of ECMP routes.
max-ecmp-num number
By default, the maximum number of
ECMP routes is 16.
Route backup
Route backup can help improve network availability. Among routes to the same destination, the route
with the highest preference is the primary route and others are secondary routes.
The router forwards matching packets through the primary route. When the primary route fails, the route
with the highest preference among the secondary routes is selected to forward packets. When the
primary route recovers, the router uses it to forward packets.
Route recursion
To use a BGP, static, or RIP route that has an indirectly connected next hop, a router must perform route
recursion to find the output interface to reach the next hop.
Link-state routing protocols, such as OSPF and IS-IS, do not need route recursion, because they obtain
directly connected next hops through route calculation.