Data Preparation
To configure an NSSA, you need the following data.
No.
Data
1
(Optional) Cost of the default route to the NSSA
NOTE
By default, the cost of the default route to the NSSA is 1.
Procedure
Step 1
Run:
system-view
The system view is displayed.
Step 2
Run:
ospf
[
process-id
]
The OSPF process view is displayed.
Step 3
Run:
area
area-id
The OSPF area view is displayed.
Step 4
Run:
nssa
[
default-route-advertise
|
flush-waiting-timer
interval-value
|
no-import-
route
|
no-summary
|
set-n-bit
|
suppress-forwarding-address
|
translator-always
|
translator-interval
interval-value
|
zero-address-forwarding
]
*
The specified area is configured as an NSSA.
NOTE
l
All switches in the NSSA must be configured with NSSA attributes using the
nssa
command.
l
Configuring or deleting NSSA attributes may trigger routing update in the area. A second configuration
of NSSA attributes can be implemented or canceled only after routing update is complete.
The
nssa
command is applicable to the following scenarios:
l
The parameter
default-route-advertise
is used to advertise Type 7 LSAs carrying the default
route on the ABR or ASBR to the NSSA.
Type 7 LSAs carrying the default route will be generated regardless of whether the default
route 0.0.0.0 exists in the routing table on the ABR. On the ASBR, however, the default Type
7 LSA is generated only when the default route 0.0.0.0 exists in the routing table.
l
When the area to which the ASBR belongs is configured as an NSSA, invalid Type 5 LSAs
from other switches in the area where LSAs are flooded will be reserved. These LSAs will
be deleted only when the aging time reaches 3600s. The switch performance is affected
because the forwarding of a large number of LSAs consumes the memory resources. To
resolve such a problem, you can set the parameter
flush-waiting-timer
to the maximum
value 3600s for Type 5 LSAs so that the invalid Type 5 LSAs from other switches can be
deleted in time.
S6700 Series Ethernet Switches
Configuration Guide - IP Routing
4 OSPF Configuration
Issue 01 (2012-03-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
119