Operation Manual – IPv4 RoutingH3C S7500E Series Ethernet Switches Chapter 5 BGP Configuration5-235.4.2 Configuring BGP Route RedistributionBGP can advertise the routing information of the local AS to peering ASs, but itredistributes routing information from IGP into BGP rather than self-finding. Duringroute redistribution, BGP can filter routing information from specific routing protocols.Follow these steps to configure BGP route redistribution:To do… Use the command… RemarksEnter system view system-view —Enter BGP view bgp as-number —Enable BGP toredistribute default routeinto the BGP routing tabledefault-route imported OptionalNot enabled by defaultRedistribute routes fromanother routing protocolimport-route protocol[ process-id [ medmed-value | route-policyroute-policy-name ] * ]RequiredNot redistributed bydefaultInject a network to theBGP routing tablenetwork ip-address[ mask | mask-length ][ short-cut | route-policyroute-policy-name ]OptionalNot injected by defaultNote:z The ORIGIN attribute of routes redistributed using the import-route command isIncomplete.z The ORIGIN attribute of networks advertised into the BGP routing table with thenetwork 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 SummarizationTo reduce the routing table size on medium and large BGP networks, you need toconfigure route summarization on peers. BGP supports two summarization modes:automatic and manual.z Automatic summarization: Summarizes redistributed IGP subnets. With thefeature configured, BGP advertises only summary natural networks rather thansubnets. The default route and routes injected with the network command can notbe summarized.z Manual summarization: Summarizes BGP local routes. The manual summaryroutes enjoy higher priority than automatic ones.
