Configuring Default Route Origination - Dell PowerConnect B-FCXs Configuration Manual

PowerConnect(config-ospf-router)#summary-address 10.1.0.0 255.255.0.0
The command in this example configures summary address 10.1.0.0, which includes addresses
10.1.1.0, 10.1.2.0, 10.1.3.0, and so on. For all of these networks, only the address 10.1.0.0 (the
parent route) is advertised in external LSAs. However, if the parent route has not been configured
with a summary address, or if the summary address for the parent route is configured after the
child route, the Layer 3 switch will advertise all routes. For example:
router ospf
area 0
summary-address 10.1.1.0 255.255.0.0 -> Advertised
summary-address 10.1.2.0 255.255.0.0 -> Advertised
summary-address 10.0.0.0 255.0.0.0 -> Advertised
Syntax: summary-address <ip-addr> <ip-mask>
The <ip-addr> parameter specifies the network address.
The <ip-mask> parameter specifies the network mask.
To display the configured summary addresses, use the show ip ospf config command at any level of
the CLI. The summary addresses display at the bottom of the output as shown in the following
example.
PowerConnect#show ip ospf config
some lines omitted for brevity...
OSPF Redistribution Address Ranges currently defined:
Range-Address
1.0.0.0
1.0.1.0
1.0.2.0
Syntax: show ip ospf config

Configuring default route origination

When the Layer 3 Switch 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, Layer 3 Switches do not advertise the default route into the OSPF domain. If you want
the Layer 3 Switch to advertise the OSPF default route, you must explicitly enable default route
origination.
When you enable OSPF default route origination, the Layer 3 Switch 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 Layer 3 Switch 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
Layer 3 Switches never advertise the OSPF default route, regardless of other configuration
parameters, unless you explicitly enable default route origination using the following method.
PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Subnetmask
255.0.0.0
255.255.255.0
255.255.255.0
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Configuring OSPF
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