Configure Default Route Origination - Dell PowerConnect B-RX Configuration Manual

Range-Address
1.0.0.0
1.0.1.0
1.0.2.0
Syntax: show ip ospf config

Configure default route origination

When the BigIron RX is an OSPF Autonomous System Boundary Router (ASBR), you can configure it
to automatically generate a default external route into an OSPF routing domain. This feature is
called "default route origination" or "default information origination".
By default, the BigIron RX does not advertise the default route into the OSPF domain. If you want
the BigIron RX to advertise the OSPF default route, you must explicitly enable default route
origination.
When you enable OSPF default route origination, the BigIron RX advertises a type 5 default route
that is flooded throughout the AS (except stub areas and NSSAs). In addition, internal NSSA ASBRs
advertise their default routes as translatable type 7 default routes.
The BigIron RX advertises the default route into OSPF even if OSPF route redistribution is not
enabled, and even if the default route is learned through an IBGP neighbor.
NOTE
BigIron RX never advertises the OSPF default route, regardless of other configuration parameters,
unless you explicitly enable default route origination using the following method.
If the BigIron RX is an ASBR, you can use the "always" option when you enable the default route
origination. The always option causes the ASBR to create and advertise a default route if it does not
already have one configured.
If default route origination is enabled and you disable it, the default route originated by the BigIron
RX is flushed. Default routes generated by other OSPF routers are not affected. If you re-enable the
feature, the feature takes effect immediately and thus does not require you to reload the software.
NOTE
The ABR (BigIron RX) will not inject the default route into an NSSA by default and the command
described in this section will not cause the BigIron RX to inject the default route into the NSSA. To
inject the default route into an NSSA, use the area <num> | <ip-addr> nssa
default-information-originate command. Refer to
page 681.
To enable default route origination, enter the following command.
BigIron RX(config-ospf-router)# default-information-originate
To disable the feature, enter the following command.
BigIron RX(config-ospf-router)# no default-information-originate
Syntax: [no default-information-originate [always] [metric <value>] [metric-type <type>]
The always parameter advertises the default route regardless of whether the router has a default
route. This option is disabled by default.
The metric <value> parameter specifies a metric for the default route. If this option is not used, the
default metric is used for the route.
BigIron RX Series Configuration Guide
53-1001986-01
Subnetmask
255.0.0.0
255.255.255.0
255.255.255.0
Configuring OSPF
"Assign a Not-So-Stubby Area (NSSA)"
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