HP VPN Firewall Appliances Network Management Configuration Guide

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Route summarization reduces the routing information exchanged between areas and the sizes of routing
tables, improving router performance.
1. Configuring route summarization on an ABR
After you configure a summary route on an ABR, the ABR generates a summary LSA instead of
more specific LSAs so that the scale of LSDBs on routers in other areas and the influence of
topology changes are reduced.
For example, three internal routes 19.1.1.0/24, 19.1.2.0/24, and 19.1.3.0/24 are available
within an area. You can summarize the three networks into the network 19.1.0.0/16, and
advertise the summary network other areas.
To configure route summarization on an ABR:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter OSPF view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
N/A
3. Enter OSPF area view.
area area-id N/A
4. Configure ABR route
summarization.
abr-summary ip-address { mask |
mask-length } [ advertise |
not-advertise ] [ cost cost ]
Not configured by default.
The command is available on an
ABR only.
2. 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 within the specified address range. If the ASBR is
in an NSSA area, it also summarizes Type-7 LSAs within 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:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter OSPF view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ]*
N/A
3. Configure ASBR route
summarization.
asbr-summary ip-address { mask |
mask-length } [ tag tag |
not-advertise | cost cost ] *
The command is available on an
ASBR only.
Not configured by default.
Configuring OSPF inbound route filtering
Perform this task to filter routes calculated using received LSAs.
The following filtering methods are available:
• Use an ACL or IP prefix list to filter routing information by destination address.
• Use the gateway keyword to filter routing information by next hop.