Specifications
Implementing OSPF on Cisco IOS XR Software
How to Implement OSPF on Cisco IOS XR Software
RC-246
Cisco IOS XR Routing Configuration Guide
Step 5
stub [no-summary]
or
nssa [no-redistribution] 
[default-information-originate] [no-summary]
Example:
RP/0/RP0/CPU0:router(config-ospf-ar)# stub no 
summary
or
RP/0/RP0/CPU0:router(config-ospf-ar)# nssa 
no-redistribution
Defines the nonbackbone area as a stub area.
• See the “Configuring Stub and Not-so-Stubby Area 
Types” section on page 244.
• Specify the no-summary keyword to further reduce the 
number of LSAs sent into a stub area. This keyword 
prevents the ABR from sending summary link-state 
advertisements (Type 3) in the stub area.
or
Defines an area as an NSSA.
• See the “Configuring Stub and Not-so-Stubby Area 
Types” section on page 244.
Step 6
stub
or
nssa
Example:
RP/0/RP0/CPU0:router(config-ospf-ar)# stub 
or
RP/0/RP0/CPU0:router(config-ospf-ar)# nssa 
(Optional) Turns off the options configured for stub and 
NSSA areas. 
• If you configured the stub and NSSA areas using the 
optional keywords (no-summary, no-redistribution, 
default-information-originate, and no-summary) in 
Step 5, you must now reissue the stub and nssa 
commands without the keywords—rather than using 
the no form of the command.
• For example, the no nssa 
default-information-originate form of the command 
changes the NSSA area into a normal area that 
inadvertently brings down the existing adjacencies in 
that area.
Step 7
default-cost 
cost
Example:
RP/0/RP0/CPU0:router(config-ospf-ar)#
default-cost 15
(Optional) Specifies a cost for the default summary route 
sent into a stub area or an NSSA.
• Use this command only on ABRs attached to the NSSA. 
Do not use it on any other routers in the area.
• The default cost is 1.
Command or Action Purpose










