3Com Switch 7750 Configuration Guide Guide

Configuring the Way to Advertise/Receive Routing Information 343
You can filter IGP routing information by routing protocols before the IGP routing
information is imported to BGP routing table.
c
CAUTION:
■ If a route is imported to the BGP routing table through the import-route
command, its Origin attribute is Incomplete.
■ The network segment route to be advertised must be in the local IP routing
table. You can use routing policy to control route advertising with more
flexibility.
■ The Origin attribute of the network segment routes advertised to BGP routing
table through the network command is IGP.
Configuring BGP Route
Aggregation
In a medium-/large-sized BGP network, you can reduce the number of the routes
to be advertised to BGP peers through route aggregation to save the spaces of
BGP peer routing tables. BGP supports two route aggregation modes: automatic
aggregation mode and manual aggregation mode.
■ Automatic aggregation mode, where IGP sub-network routes imported by BGP
are aggregated. In this mode, only the aggregated routes are advertised. The
imported IGP sub-network routes are not advertised. Note that the default
routes and the routes imported by using the network command cannot be
automatically aggregated.
■ Manual aggregation mode, where local BGP routes are aggregated. The
priority of manual aggregation is higher than that of automatic aggregation.
Table 274 Import routes
Operation Command Description
Enter system view system-view -
Enable BGP, and enter BGP
view
bgp as-number
Required
By default, BGP is disabled.
Import and advertise routing
information generated by
other protocols.
import-route protocol [
process-id ] [ med med-value |
route-policy
route-policy-name ]*
Required
By default, BGP does not
import nor advertise the
routing information
generated by other protocols.
Advertise network segment
routes to BGP routing table
network network-address [
mask ] route-policy
route-policy-name ]
Optional
By default, BGP does not
advertise any network
segment routes. Optional
By default, BGP does not
advertise any network
segment routes. Optional
By default, BGP does not
advertise any network
segment routes.
Table 275 Configure BGP route aggregation
Operation Command Description
Enter system view system-view -