OSPFv3 areas

After OSPFv3 is enabled, you can assign OSPFv3 areas. You can specify the area id in plain number format , such as "area 1", or in ipv4 address format, such as 10.1.1.1. Each device interface can support one area.
Note: You can assign only one area on a device interface.
Note: You are required to configure a router ID when running only IPv6 routing protocols.
Note: By default, the router ID is the IPv4 address configured on the lowest-numbered loopback interface. If the device does not have a loopback interface, the default router ID is the highest-numbered IPv4 address configured on the device. You can also configure router id using the ip router-id command.
Note: For the ICX 7150, a maximum of 4 OSPF areas is supported for each OSPF instance.

In this section:

  1. Backbone area
    The backbone area (also known as area 0 or area 0.0.0.0) forms the core of OSPF networks. All other areas should be connected to the backbone area either by a direct link or by virtual link configuration. Routers that have interfaces in both backbone area and (at least one) non-backbone area are called Area Border Routers (ABR). Inter area routing happens via ABRs.
  2. Area range
    You can further consolidate routes at an area boundary by defining an area range. The area range allows you to assign an aggregate address to a range of IP and IPv6 addresses.
  3. Area types
    OSPFv3 areas can be normal, a stub area, a totally stubby area (TSA), or a not-so-stubby area (NSSA).
  4. Assigning OSPFv3 areas
    Areas can be assigned as OSPFv3 areas.
  5. Assigning OSPFv3 areas to interfaces
    Defined OSPFv3 areas can be assigned to device interfaces.
  6. Stub area and totally stubby area
    A stub area is an area in which advertisements of external routes are not allowed, reducing the size of the database. A totally stubby area (TSA) is a stub area in which summary link-state advertisement (type 3 LSAs) are not sent. A default summary LSA, with a prefix of 0.0.0.0/0 is originated into the stub area by an ABR, so that devices in the area can forward all traffic for which a specific route is not known, via ABR.
  7. Configuring a stub area
    OSPFv3 areas can be defined as stub areas with modifiable parameters.
  8. Not-so-stubby area
    A not-so-stubby-area (NSSA) is an OSPFv3 area that provides the benefits of stub areas with the extra capability of importing external route information. OSPFv3 does not flood external routes from other areas into an NSSA, but does translate and flood route information from the NSSA into other areas such as the backbone.
  9. Configuring an NSSA
    OSPFv3 areas can be defined as NSSA areas with configurable parameters.
  10. LSA types for OSPFv3
    Communication among OSPFv3 areas is provided by means of link-state advertisements (LSAs). OSPFv3 supports a number of types of LSAs:
Parent topic: OSPFv3