Load Balancing And Route Backup - 3Com S7906E Configuration Manual

Routing approach
OSPF NSSA
IBGP
EBGP
UNKNOWN
The smaller the priority value, the higher the priority.
The priority for a direct route is always 0, which you cannot change. Any other type of routes can
have their priorities manually configured.
Each static route can be configured with a different priority.
IPv4 and IPv6 routes have their own respective routing tables.

Load Balancing and Route Backup

Load Balancing
In multi-route mode, a routing protocol can be configured with multiple equal-cost routes to the same
destination. These routes have the same priority and will all be used to accomplish load balancing if
there is no route with a higher priority available. A given routing protocol may find several routes with the
same metric to the same destination, and if this protocol has the highest priority among all the active
protocols, these routes will be considered valid routes for load balancing.
The number of routes for load balancing is 8.
In current implementations, routing protocols supporting load balancing are static routing, RIP,
OSPF, BGP, and IS-IS.
Route backup
Route backup can help improve network reliability. With route backup, you can configure multiple routes
to the same destination, expecting the one with the highest priority to be the main route and all the rest
backup routes.
Under normal circumstances, packets are forwarded through the main route. When the main route goes
down, the route with the highest priority among the backup routes is selected to forward packets. When
the main route recovers, the route selection process is performed again and the main route is selected
again to forward packets.
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255
255
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1-5
Priority