Riverstone Networks WICT1-12 - Manual (Page 221)

Riverstone Networks RS Switch Router User Guide Release 8.0 14-5
OSPF Configuration Guide Configuring OSPF Areas
Additionally, there may be interfaces that are directly attached to the router and therefore should be advertised as
reachable from the router. To specify an interface that is directly attached, such as a loopback interface, together with
its cost, enter the following command in Configure mode..
14.5.3 Configuring Not-So-Stubby Areas (NSSA)
NSSAs are similar to stub areas, in that they cannot be used as transit areas. But unlike stub areas, NSSAs can originate
and advertise Type-7 LSAs. Type-7 LSAs carry external route information within an NSSA. They are advertised only
within a single NSSA; they are not flooded into the backbone area or any other area by border routers. (Type-7 LSAs
have the same syntax as Type-5 LSAs, except for the link state type.) In addition, NSSA border routers translate Type-7
LSAs into Type-5 LSAs and flood them to all Type-5 capable areas.
The RS supports the configuration of NSSAs and the ability to add networks to an NSSA. To define an area as an
NSSA, enter the following command in Configure mode:
• The
nssa-cost
parameter specifies the cost used to inject a default route into an NSSA area. If this
parameter is not specified, no default route is injected into the NSSA area.
To add a network to an NSSA area, enter the following command in Configure mode:
• The
restrict
keyword is used to prevent the network from being advertised in Type 7 LSAs.
Add a stub host to an OSPF area. ospf add stub-host to-area
<area-ID>
|backbone cost
<num>
Configures an NSSA.
ospf set area
<area-number>
nssa nssa-cost
<number>
Adds an NSSA network to an NSSA. ospf add nssa-network
<IPaddr-mask>
to
area
<area-addr>
[restrict][host-net]