Configuring Ospf Route Control; Configuration Prerequisites; Configuring Ospf Route Summarization - HPE FlexNetwork HSR6800 Configuration Manual

Configuring OSPF route control

This section describes how to control the advertisement and reception of OSPF routing information,
as well as route redistribution from other protocols.

Configuration prerequisites

Before you configure OSPF route control, complete the following tasks:
•
Configure IP addresses for interfaces.
•
Enable OSPF.
•
Configure filters if routing information filtering is needed.

Configuring OSPF route summarization

You can configure route summarization on an ABR or ASBR to summarize routes with the same
prefix into a single route and distribute it to other areas.
Route summarization reduces the routing information exchanged between areas and the sizes of
routing tables, improving router performance.
Configuring route summarization on an ABR
If contiguous network segments are available in the area, you can summarize them into a single
network segment. An ABR generates Type-3 LSAs on a per network segment basis for an attached
non-backbone area. In this way, the ABR in the area distributes only the summary LSA to reduce the
scale of LSDBs on routers in other areas and the influence of topology changes.
For example, in an area are three internal routes 19.1.1.0/24, 19.1.2.0/24, and 19.1.3.0/24. By
configuring route summarization on the ABR, the three routes are summarized into the route
19.1.0.0/16 that is advertised to other areas.
To configure route summarization on an ABR:
Step
Enter system view.
1.
Enter OSPF view.
2.
Enter OSPF area view.
3.
Configure ABR route
4.
summarization.
Configuring route summarization when redistributing routes into OSPF on an ASBR
Without route summarization, an ASBR advertises each redistributed route in a separate ASE LSA.
After a summary route is configured, the ASBR advertises only the summary route in an ASE LSA
instead of more specific routes, reducing the number of LSAs in the LSDB.
The ASBR summarizes redistributed Type-5 LSAs that fall into the specified address range. If the
ASBR is in an NSSA area, it also summarizes Type-7 LSAs that fall into the specified address range.
If the ASBR is also the ABR, it summarizes Type-5 LSAs translated from Type-7 LSAs.
To configure route summarization when redistributing routes into OSPF on an ASBR:
Command
system-view
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
area area-id
abr-summary ip-address { mask |
mask-length } [ advertise |
not-advertise ] [ cost cost ]
69
Remarks
N/A
N/A
N/A
Not configured by default.
The command is available on an
ABR only.