Configuring IPv4 OSPFv2 Areas in Gaia Clish
|
Important - In a Cluster |
For description of OSPFv2 Areas, see IPv4 OSPF Types of Areas.
The configuration is applicable to OSPF Multiple Instances (see Configuring IPv4 OSPFv2 Multiple Instances).

An OSPF area defines a group of routers, which run OSPF and have complete topology information for the given area.
An OSPF area uses an Area Border Router (ABR) to exchange routing information with other areas via the backbone area.
Routes for a given area are summarized into the backbone area.
The backbone area then redistributes this summary information to other areas.
By definition, an ABR has interfaces to more than one area.
One of those areas must be either the backbone or an OSPF Virtual Link to the backbone.
OSPF forces a hub and spoke area topology, with the backbone area always being the hub.

|

Parameter |
Description |
||
---|---|---|---|
|
Specifies an OSPF Area ID (for this OSPF Instance).
Range:
Default: none |
||
|
Configures this area as a Not-So-Stubby Area. A Not-So-Stubby Area is an OSPF Stub Area, which can carry routes learned by other protocols such as BGP or RIP.
|
||
|
Configures the routing cost associated with the default route for this area. The higher the cost, the less preferred the route. Range: 1-16777215, or default Default: 1 |
||
|
Configures the default route type for the Not-So-Stubby Area (NSSA).
Range: 1, or 2 Default: 1 |
||
|
Disables ( OSPF routers send packets called Link State Advertisements (LSAs) to all adjacent routers in an area. Areas are smaller groups within the Autonomous System that can be defined in order to limit the flooding of LSAs. Many LSA types do not leave the area from which they originated. This increases efficiency and saves network bandwidth. Type 3 LSAs are originated by Area Border Routers (ABRs) and are flooded to adjacent routers in a given area. Each Type 3 LSA describes a route to a network which is external to the area but is internal to the local Autonomous System. Range: Default: |
||
|
Removes ( Range: Default: none |
||
|
Removes (
An IPv4 address range is defined by a prefix and a mask length in CIDR notation format (for example, 192.168.1.0/24). An area can be configured with any number of address ranges. These ranges are used to reduce the number of routing entries that an area will emit into the backbone area (and hence all areas). If a given prefix aggregates a number of more specific prefixes within an area, then an address range can be configured and will be the only prefix advertised into the backbone.
Range: off, on, or restrict Default: none |
||
|
Controls if both Type 5 LSAs and Type 7 LSAs ( This is only relevant when the router is an NSSA Border Router. Range: Default: |
||
|
Configures the translation of Type 7 LSAs into Type 5 LSAs. Specifies whether or not this NSSA Border Router unconditionally translates Type 7 LSAs into Type 5 LSAs.
If the NSSA router is not an Area Border Router, this option does not have any effect. Range: always, or candidate Default: candidate |
||
|
Configures the Translator Stability Interval. This time controls how long this Type 7 LSA translator continues to perform its translator duties once it determined that it is no longer the elected translator. Range: 1-655335 seconds, or default Default: 40 seconds |
||
|
Removes ( |
||
|
Configures an OSPF address range for this area. An IPv4 address range is defined by a prefix and a mask length in CIDR notation format (for example, 192.168.1.0/24). An area can be configured with any number of address ranges. These ranges are used to reduce the number of routing entries that an area will emit into the backbone area (and hence all areas). If a given prefix aggregates a number of more specific prefixes within an area, then an address range can be configured and will be the only prefix advertised into the backbone.
|
||
|
Removes (
Range: off, on, or restrict Default: none |
||
|
Configures this area as a Stub Area. Stub areas do not allow Type 5 LSAs to be propagated into or throughout the area and instead depend on default routing for external destinations. You can configure an area as a Stub Area to reduce the number of entries in the routing table. Routes external to the OSPF domain are not added to the routing table.
|
||
|
Configures the routing cost associated with the default route for this area. The higher the cost, the less preferred the route. Range: 1-16777215, or default Default: 1 |
||
|
Disables (
Range: Default: |
||
|
Disables ( A Totally-Stubby Area does not have Type 4 or Type 5 LSAs. It has only a single Type 3 LSA, which describes a default route.
Range: Default: |
||
|
Configures a Stub Network for this area. A network address is defined by a prefix and a mask length in CIDR notation format (for example, 192.168.1.0/24). OSPF can advertise routes of networks, which are not running OSPF by using a stub network. The advertised routes appear as OSPF internal routes, and can be filtered for export at area borders using OSPF area ranges. Any advertised network prefix must be directly connected to the router, where the stub network is configured. Meaning, one of the router's interface addresses must be within the network to be included in the router LSA. For OSPFv2, IPv4 Stub hosts may be configured by using a mask length of 32. For OSPFv3, IPv6 Stub hosts may be configured by using a mask length of 128. This feature also supports advertising a network that can be activated by the local address of a point-to-point interface. To advertise reachability to such an network, you must configure an IP address for the network along with a non-zero cost. |
||
|
Controls the stub network for this area:
Range: Default: none |
||
|
Configures the cost associated with the stub network as reached through this router. The higher the cost, the less preferred the route. Range: 1-65535, or default Default: 1 |