H3C Technologies H3C S7500E Series Switches - Manual (Page 23)

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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, see the Layer 3 - IP Routing Configuration Guide.
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… Use the command… Remarks
Enter system view system-view —
Configure a router ID router id router-id
Optional
Not configured by default.
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.
A route ID is selected in the following sequence: