HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Routing Configuration Gu - Page 74

Configuring route summarization when redistributing routes into OSPF on an ASBR

Page 74 highlights

To configure route summarization on an ABR: Step 1. Enter system view. 2. Enter OSPF view. 3. Enter OSPF area view. 4. Configure ABR route summarization. Command Remarks system-view N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A area area-id N/A abr-summary ip-address { mask | mask-length } [ advertise | not-advertise ] [ cost cost ] By default, no route summarization is configured. The command takes effect only on an ABR. 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 you configure a summary route, 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: Step 1. Enter system view. 2. Enter OSPF view. 3. Configure ASBR route summarization. Command Remarks system-view N/A ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ]* N/A asbr-summary ip-address { mask | mask-length } [ tag tag | not-advertise | cost cost ] * By default, no ASBR route summarization is configured. The command takes effect only on an ASBR. Configuring inbound OSPF 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. • Use an ACL or IP prefix list to filter routing information by destination address and at the same time use the gateway keyword to filter routing information by next hop. • Use a routing policy to filter routing information. To configure OSPF to filter routes calculated using received LSAs: Step 1. Enter system view. Command system-view Remarks N/A 63

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63
To configure route summarization on an ABR:
Step
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
]
By default, no route summarization
is configured.
The command takes effect only on
an ABR.
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
you configure a summary route, 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:
Step
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
] *
By default, no ASBR route
summarization is configured.
The command takes effect only on an
ASBR.
Configuring inbound OSPF 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.
Use an ACL or IP prefix list to filter routing information by destination address and at the same time
use the
gateway
keyword to filter routing information by next hop.
Use a routing policy to filter routing information.
To configure OSPF to filter routes calculated using received LSAs:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A