Creating OSPF area ranges

Create an area address range on the OSPF router to reduce the number of area border router (ABR) advertisements into other OSPF areas. An area address range is an implied contiguous range of area network addresses for which the ABR advertises a single summary route.

Before you begin

You must create the OSPF area.
You configure OSPF on a VRF instance the same way you configure the GlobalRouter, except that you must use VRF Router configuration mode and replace ipv6 with ipv6 ospf.

About this task

If you create two ranges, and one range is a subset of the other, the router uses the most specific match.

Procedure

Enter OSPF Router Configuration mode:

enable

configure terminal

router ospf
Create an area range:

ipv6 area range {A.B.C.D} WORD<0-255> [inter-area-prefix-link|nssa-extlink] advertise-mode <advertise|not-advertise> [advertise-metric <0-65535>]

Example

Create an area range:

Switch:1(config-ospf)#ipv6 area range 0.0.0.1 3000::0/16 advertise-mode advertise

Variable definitions

Use the data in the following table to use the ipv6 area range command.


Variable	Value
{A.B.C.D}	Specifies the area in which the address aggregate exists. Use dotted decimal notation to specify the area name.
advertise-metric `<0-65535>`	Specifies a cost value to advertise for the OSPF area range. This value applies to summary LSAs (Type 3). If the value is 0, OSPF uses the cost to the farthest point in the network that is summarized.
advertise-mode <advertise\|not-advertise>	Specifies the advertisement mode for prefixes in the range. advertise advertises the aggregate summary LSA with the same link-state ID. not-advertise does not advertise networks that fall within the range. The default is advertise.
<inter-area-prefix-link\|nssa-extlink>	Specifies the area LSDB type to which the address aggregate applies. inter-area-prefix-link generates an aggregated summary. nssa-extlink generates an NSSA link summary.
`WORD<0-255>`	Specifies the IPv6 address and prefix.