H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – IPv4 Routing
H3C S7500E Series Ethernet Switches Chapter 5 BGP Configuration
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5.4.2 Configuring BGP Route Redistribution
BGP can advertise the routing information of the local AS to peering ASs, but it
redistributes routing information from IGP into BGP rather than self-finding. During
route redistribution, BGP can filter routing information from specific routing protocols.
Follow these steps to configure BGP route redistribution:
To do… Use the command… Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Enable BGP to
redistribute default route
into the BGP routing table
default-route imported
Optional
Not enabled by default
Redistribute routes from
another routing protocol
import-route protocol
[ process-id [ med
med-value | route-policy
route-policy-name ] * ]
Required
Not redistributed by
default
Inject a network to the
BGP routing table
network ip-address
[ mask | mask-length ]
[ short-cut | route-policy
route-policy-name ]
Optional
Not injected by default
 Note:
z The ORIGIN attribute of routes redistributed using the import-route command is
Incomplete.
z The ORIGIN attribute of networks advertised into the BGP routing table with the
network command is IGP. These networks must exist in the local IP routing table,
and using a routing policy makes routes control more flexible.
5.4.3 Configuring BGP Route Summarization
To reduce the routing table size on medium and large BGP networks, you need to
configure route summarization on peers. BGP supports two summarization modes:
automatic and manual.
z Automatic summarization: Summarizes redistributed IGP subnets. With the
feature configured, BGP advertises only summary natural networks rather than
subnets. The default route and routes injected with the network command can not
be summarized.
z Manual summarization: Summarizes BGP local routes. The manual summary
routes enjoy higher priority than automatic ones.