H3C Technologies H3C S12500 Series Switches - Manual (Page 228)

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Controlling route generation
Generating BGP routes can be done in the following ways:
• Configure BGP to advertise local networks.
• Configure BGP to redistribute IGP routes.
Configuration prerequisites
Create and configure a routing policy. For more information, see "Configuring routing policies."
Injecting a local network
This task allows you to inject a network in the local routing table to the BGP routing table, so that BGP can
advertise the network to BGP peers. The network to be injected must be available and active in the local
IP routing table. The origin attribute of routes advertised in this way is IGP. You can also reference a
routing policy to flexibly control route advertisement.
To inject a local network:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Inject a local network to the
BGP routing table.
network ip-address [ mask |
mask-length ] [ route-policy
route-policy-name ]
Optional.
Not injected by default.
Redistributing IGP routes
BGP does not find routes by itself. Rather, it redistributes routing information in the local AS from IGPs.
During route redistribution, you can configure BGP to filter routing information from specific routing
protocols.
By default, BGP does not redistribute default IGP routes. You can use the default-route imported
command to redistribute default IGP routes into the BGP routing table.
Only active routes can be redistributed. You can use the display ip routing-table protocol command to
display route state information. For more information about the display ip routing-table protocol
command, see Layer 3—IP Routing Command Reference.
The origin attribute of routes redistributed from IGPs is INCOMPLETE.
To configure BGP to redistribute IGP routes: