Huawei Quidway S6500 Series Operation Manual page 181

Operation Manual - Routing Protocol
Quidway S6500 Series Ethernet Switches
4.2.13 Setting a Shortest Path First (SPF) Calculation Interval for OSPF
Whenever the LSDB of OSPF takes changes, the shortest path requires recalculation.
Calculating the shortest path upon change will consume enormous resources as well
as affect the operation efficiency of the router. Adjusting the SPF calculation interval,
however, can restrain the resource consumption due to frequent network changes.
Perform the following configuration in OSPF view.
Table 4-13 Setting the SPF calculation interval
Set the SPF calculation interval
Restore the SPF calculation interval
By default, the interval of SPF recalculation is 5 seconds.
4.2.14 Configuring STUB Area of OSPF
STUB areas are some special LSA areas, in which the ABRs do not propagate the
learned external routes of the AS. In these areas, the routing table sizes of routers and
the routing traffic are significantly reduced.
The STUB area is an optional configuration attribute, but not every area conforms to
the configuration condition. Generally, STUB areas, located at the AS boundaries, are
those non-backbone areas with only one ABR. Even if this area has multiple ABRs, no
virtual links are established between these ABRs.
To ensure that the routes to the destinations outside the AS are still reachable, the ABR
in this area will generate a default route (0.0.0.0) and advertise it to the non-ABR
routers in the area.
Please pay attention to the following items when configuring a STUB area:
The backbone area cannot be configured to be the STUB area and the virtual link
cannot pass through the STUB area.
If you want to configure an area to be the STUB area, then all the routers in this
area should be configured with this attribute.
No ASBR can exist in a STUB area. In other words, the external routes of the AS
cannot be propagated in the STUB area.
Perform the following configuration in OSPF Area view.
Operation
Huawei Technologies Proprietary
4-13
Chapter 4 OSPF Configuration
Command
spf-schedule-interval seconds
undo spf-schedule-interval seconds