3Com Switch 8800 Configuration Guide Chapter 19 OSPF Configuration
19-13
By default, OSPF will not filter the received routing information.

II. Configuring filtering the routes imported to OSPF

Use the filter-policy export command to configure the ASBR router to filter the
external routes imported to OSPF. This command is only valid for the ASBR router.
Table 19-10 Enable OSPF to filter the imported routes of other routing protocols
Operation Command
Enable OSPF to filter the routes
advertised by other routing protocols filter-policy { acl-number | ip-prefix
ip-prefix-name } export [ routing- process ]
Disable OSPF to filter the advertised
routes by other routing protocols
undo filter-policy { acl-number | ip-prefix
ip-prefix-name } export [ routing-process ]
By default, OSPF does not receive the routes advertised by other routing protocols.
Note:
z The filter-policy import command only filters the OSPF routes of this process
received from the neighbors, and routes that cannot pass the filter will not be added
to the routing table. This command only takes effect on ABR.
z The filter-policy export command only takes effect on the routes imported by the
import-route command. If you configure the switch with only the filter-policy
export command, but without configuring the import-route command to import
other external routes (including OSPF routes of different process), then the
filter-policy export command does not take effect.
z If the filter-policy export command does not specify which type of route is to be
filtered, it takes effect on all routes imported by the local device using the
import-route command.
19.2.8 Configuring the Route Summary of OSPF

I. Configuring the route summary of OSPF area

Route summary means that ABR can aggregate information of the routes of the same
prefix and advertise only one route to other areas. An area can be configured with
multiple aggregate segments, thereby OSPF can summarize them. When the ABR
transmits routing information to other areas, it will generate Sum_net_Lsa (type-3 LSA)
per network. If some continuous networks exist in this area, you can use the
abr-summary command to summarize these segments into one segment. Thus, the
ABR only needs to send an aggregated LSA, and all the LSAs in the range of the