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934 PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Configuring OSPF
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When an NSSA contains more than one ABR, OSPF elects one of the ABRs to perform the
LSA translation for NSSA. OSPF elects the ABR with the highest router ID. If the elected
ABR becomes unavailable, OSPF automatically elects the ABR with the next highest router
ID to take over translation of LSAs for the NSSA. The election process for NSSA ABRs is
automatic.
Example
To set up the OSPF areas shown in Figure 138 on page 923, enter the following commands.
PowerConnect(config-ospf-router)#area 192.5.1.0
PowerConnect(config-ospf-router)#area 200.5.0.0
PowerConnect(config-ospf-router)#area 195.5.0.0
PowerConnect(config-ospf-router)#area 0.0.0.0
PowerConnect(config-ospf-router)#write memory
Syntax: area <num> | <ip-addr>
The <num> | <ip-addr> parameter specifies the area number, which can be a number or in IP
address format. If you specify a number, the number can be from 0 through 18.
NOTE
You can assign one area on a router interface. For example, if the system or chassis module has 16
ports, 16 areas are supported on the chassis or module.
Assigning a totally stubby area
By default, the Layer 3 Switch sends summary LSAs (LSA type 3) into stub areas. You can further
reduce the number of link state advertisements (LSAs) sent into a stub area by configuring the
Layer 3 Switch to stop sending summary LSAs (type 3 LSAs) into the area. You can disable the
summary LSAs when you are configuring the stub area or later after you have configured the area.
This feature disables origination of summary LSAs, but the Layer 3 Switch still accepts summary
LSAs from OSPF neighbors and floods them to other neighbors. The Layer 3 Switch can form
adjacencies with other routers regardless of whether summarization is enabled or disabled for
areas on each router.
When you enter a command or apply a Web management option to disable the summary LSAs, the
change takes effect immediately. If you apply the option to a previously configured area, the Layer
3 Switch flushes all of the summary LSAs it has generated (as an ABR) from the area.
NOTE
This feature applies only when the Layer 3 Switch is configured as an Area Border Router (ABR) for
the area. To completely prevent summary LSAs from being sent to the area, disable the summary
LSAs on each OSPF router that is an ABR for the area.
This feature does not apply to Not-So-Stubby Areas (NSSAs).
To disable summary LSAs for a stub area, enter commands such as the following.
PowerConnect(config-ospf-router)#area 40 stub 99 no-summary
Syntax: area <num> | <ip-addr> stub <cost> [no-summary]
The <num> | <ip-addr> parameter specifies the area number, which can be a number or in IP
address format. If you specify a number, the number can be from 0 through 18.