Enables privileged EXEC mode.

Enter your password, if prompted.

Enters global configuration mode.

Enables OSPFv3 routing and enters router configuration mode.

process-id : The process ID is an internally used, identification parameter that is locally assigned. Each OSPF has a unique process ID.

Process ID can be a positive integer from 1 to 65535.

Configures an NSSA area and sets the default advertisement to this NSSA area.

• default-information-originate : Select on an ABR to allow importing type 7 LSAs into the NSSA.

• nssa-only : Advertises the summary only as a Type 7 LSA into NSSA areas

(Optional) Enables address family configuration mode for Open Shortest Path First version 3 (OSPFv3).

• The address-family ipv4 unicast command configures an IPv4 address family.

• The address-family ipv6 unicast command configures an IPv6 address family.

Controls the route summarization and filtering during the translation and limits the summary to NSSA areas

• ip-prefix : The summarized IPv4 network address and the network mask for the summary route.

• ipv6-prefix : The summarized IPv6 network address and the network mask for the summary route.

• not-advertise : (Optional) Suppresses the summary route advertisement.

• tag tag : (Optional) Associates a tag with the summary route for policy or routing decisions.

• nssa-only : (Optional) Advertises the summary only as a Type 7 LSA for NSSA areas.

Exits address-family router configuration mode and returns to the router configuration mode.

Redistributes routes from one routing domain into another routing domain.

• protocol : Specifies the source of the routes to be redistributed. Common options include:

  • connected : Redistributes directly connected networks that are not already part of the OSPF process.

  • static : Redistributes static routes configured on the router.

  • bgp : Redistributes routes learned via BGP.

  • eigrp : Redistributes routes learned via EIGRP.

  • rip : Redistributes routes learned via RIP.

  • ospf : Redistributes routes from another OSPF process (e.g., if running multiple OSPF instances or different process IDs).

  • isis : Redistributes routes learned via IS-IS.

• process-id : (Optional) If the source protocol (e.g., EIGRP, OSPF, RIP) uses a process ID, you specify it here to identify the specific instance from which routes should be taken.

• as-number : (Optional) If the source protocol (e.g., BGP or EIGRP) uses an Autonomous System (AS) number, you specify it here. This is often used interchangeably with process-id for protocols that use AS numbers.

• include-connected {level-1 | level-1-2 | level-2} : (Optional) This parameter is typically specific to IS-IS redistribution into OSPF, or sometimes OSPF into IS-IS, or even OSPF into OSPF (though less common). It refers to the IS-IS routing levels:

  • level-1: Redistributes Level-1 IS-IS routes.

  • level-2: Redistributes Level-2 IS-IS routes.

  • level-1-2: Redistributes both Level-1 and Level-2 IS-IS routes.

  • This part of the syntax suggests a context where IS-IS is the source protocol.

• metric {metric-value | transparent} : This is a critical parameter for redistribution. When routes are redistributed from one protocol to another, they need to be assigned a metric that is meaningful to the destination protocol.

  • metric-value : A specific numerical value to assign as the metric. The meaning of this value depends on the destination protocol (e.g., hop count for RIP, cost for OSPF).

  • transparent : This attempts to carry the original metric information across, but its effectiveness can vary depending on the protocols involved.

• metric-type type-value : (Optional) For OSPF, this is crucial for how external routes are handled:

  • type-1 (E1): The cost to the external destination is the sum of the external metric and the internal OSPF cost to reach the ASBR. This is often preferred for more accurate path selection.

  • type-2 (E2): The cost to the external destination is only the external metric, regardless of the internal OSPF cost to reach the ASBR. This is the default if not specified. Type 2 routes are always preferred over Type 1 routes if their external metric is the same.

• match {internal | external 1 | external 2} : This parameter is specific to OSPF when redistributing OSPF routes into another protocol. It allows you to specify which types of OSPF routes to redistribute:

  • internal : Redistributes OSPF intra-area (Type 1) and inter-area (Type 2) routes.

  • external 1 : Redistributes OSPF external Type 1 routes.

  • external 2 : Redistributes OSPF external Type 2 routes.

• nssa-only : (Optional) This keyword is specifically used when redistributing routes into a Not-So-Stubby Area (NSSA). When nssa-only is specified, the redistributed routes will be advertised as Type 7 LSAs within the NSSA, and then translated to Type 5 LSAs by the NSSA ABR for propagation to other areas. Without this, redistribution into an NSSA might not be allowed or might behave differently

• tag tag-value : (Optional) Assigns a numerical tag to the redistributed routes. This tag can be used later in route maps or distribute lists for filtering or policy-based routing.

• route-map map-tag : (Optional) A very powerful and commonly used parameter. It references a route-map that provides granular control over which routes are redistributed and how their attributes (like metric, metric-type, tag) are modified during the redistribution process.

• subnets : This parameter is specific to OSPF. By default, OSPF only redistributes classful networks. To redistribute subnetted networks (which is almost always desired in modern networks), you must include the subnets keyword. Without it, only major network numbers (e.g., 10.0.0.0/8, 192.168.1.0/24) would be redistributed.

Exits router configuration mode and returns to privileged EXEC mode.