Route Recursion; Sharing Of Routing Information; Configuring A Router Id - HP 4800G Series Configuration Manual

The number of routes for load balancing varies by device.
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.

Route Recursion

The nexthops of some BGP routes (except eBGP routes) and static routes configured with nexthops
may not be directly connected. To forward the packets, the outgoing interface to reach the nexthop must
be available. Route recursion is used to find the outgoing interface based on the nexthop information of
the route. Link-state routing protocols, such as OSPF and IS-IS, do not need route recursion because
they obtain nexthop information through route calculation.

Sharing of Routing Information

As different routing protocols use different routing algorithms to calculate routes, they may find different
routes. In a large network with multiple routing protocols, it is required for routing protocols to share their
routing information. Each routing protocol has its own route redistribution mechanism. For detailed
information, refer to the IP Routing Volume.

Configuring a Router ID

Some routing protocols use a router ID to identify a device. You can configure a global router ID for a
device. If no router ID is configured for a protocol, the global router ID is used.
To do...
Enter system view
Configure a router ID
Use the command...
system-view
router id router-id
1-5
Remarks
—
Optional
Not configured by default.