Network Router User Manual

Chapter 11: OSPF Configuration Guide
116 SmartSwitch Router User Reference Manual
Configuring OSPF Area Parameters
The SSR allows configuration of various OSPF area parameters, including stub areas, stub
cost and authentication method. Information about routes which are external to the OSPF
routing domain is not sent into a stub area. Instead, there is a default external route
generated by the ABR into the stub area for destinations outside the OSPF routing
domain. To further reduce the number of link state advertisements sent into a stub area,
you can specify the no-summary keyword with the stub option on the ABR to prevent it
from sending summary link advertisement (link state advertisements type 3) into the stub
area.
Stub cost specifies the cost to be used to inject a default route into a stub area. An
authentication method for OSPF packets can be specified on a per-area basis.
To configure OSPF area parameters, enter the following commands in the Configure
mode.
Creating Virtual Links
In OSPF, virtual links can be established:
• To connect an area via a transit area to the backbone
• To create a redundant backbone connection via another area
Each Area Border Router must be configured with the same virtual link. Note that virtual
links cannot be configured through a stub area.
Add a stub host to an OSPF area.
ospf add stub-host to-area <area-
addr>
|backbone cost <num>
Add a network to an OSPF area for
summarization.
ospf add network|summary-range
<IPaddr/mask> to-area <area-addr>|
backbone [restrict] [host-net]
Specify an OSPF area to be a stub area. ospf set area <area-num> stub [no-summary]
Specify the cost to be used to inject a
default route into a stub area.
Note:
If this command is not specified,
no default route is injected into
the OSPF stub area.
ospf set area <area-num> stub-cost <num>
Specify the authentication method to be
used by neighboring OSPF routers.
ospf set area <area-num> [stub]
[authentication-method none|simple|md5]