OSPFv3 ABR Type 3 LSA Filtering

This feature extends the ability of an Area Border Router (ABR) that is running the Open Shortest Path First version 3 (OSPFv3) protocol to filter type 3 link-state advertisements (LSAs) that are sent between different OSPFv3 areas. This feature allows only packets with specified prefixes to be sent from one area to another area and restricts all packets with other prefixes. This type of area filtering can be applied out of a specific OSPFv3 area, into a specific OSPFv3 area, or into and out of the same OSPFv3 areas at the same time.

OSPFv3 ABR Type 3 LSA Filtering

Only type 3 LSAs that originate from an ABR are filtered.

Information About OSPFv3 ABR Type 3 LSA Filtering

Area Filter Support

OSPFv3 area filters allow the filtering of inter-area prefix LSAs on the ABRs. The filter, based on IPv6 prefix lists, can be applied in both directions. In the “in” direction, it filters out the LSAs coming from all other areas when sending the inter-area prefix LSAs into the specified area. In the “out” direction, it filters out the inter-area prefix LSAs generated for the specified area.

The Area Filter Support feature gives the administrator improved control of route distribution between OSPFv3 areas.

How to Configure OSPFv3 ABR Type 3 LSA Filtering

Configuring Area Filter Support for OSPFv3

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router ospfv3 process-id
  4. area area-id filter-list prefix prefix-list-name {in | out}
  5. end
  6. ipv6 prefix-list list-name [seq seq-number ] {deny ipv6-prefix/ prefix-length | permit ipv6-prefix/ prefix-length | description text } [ge ge-value ] [le le-value ]

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

router ospfv3 process-id

Example:


Device(config)# router ospfv3 1

Configures the router to run an OSPFv3 process.

Step 4

area area-id filter-list prefix prefix-list-name {in | out}

Example:


Device(config-router)# area 1 filter-list prefix test_ipv6 out

Configures the router to filter interarea routes out of the specified area.

Step 5

end

Example:


Device(config-router)# end

Returns to global configuration mode.

Step 6

ipv6 prefix-list list-name [seq seq-number ] {deny ipv6-prefix/ prefix-length | permit ipv6-prefix/ prefix-length | description text } [ge ge-value ] [le le-value ]

Example:


Device(config)# ipv6 prefix-list test_ipv6 seq 5 permit 2011::1/128

Creates a prefix list with the name specified for the list-name argument.

Configuration Examples for OSPFv3 ABR Type 3 LSA Filtering

Example: Area Filter Support for OSPFv3

The following example shows how to configure Area Filter Support for OSPFv3: 

router ospfv3 1
!
address-family ipv4 unicast
 area 2 filter-list prefix test_ipv4 in
exit-address-family
!
address-family ipv6 unicast
 area 2 filter-list prefix test_ipv6 in 
exit-address-family
!
ip prefix-list test_ipv4 seq 5 permit 2.2.2.2/32 
! 
! 
ipv6 prefix-list test_ipv6 seq 5 deny 2011::1/128

Additional References for OSPFv3 ABR Type 3 LSA Filtering

Related Documents

Related Topic

Document Title

Configuring OSPF

“Configuring OSPF”

OSPF commands

Cisco IOS IP Routing: OSPF Command Reference

Cisco IOS master command list, all releases

Cisco IOS Master Command List, All Releases

Standards

Standard

Title

No new or modified standards are supported and support for existing standards has not been modified.

—

RFCs

RFC

Title

No new or modified RFCs are supported and support for existing RFCs has not been modified.

—

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for OSPFv3 ABR Type 3 LSA Filtering

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1. Feature Information for OSPFv3 ABR Type 3 LSA Filtering

Feature Name

Releases

Feature Information

OSPFv3 ABR Type 3 LSA Filtering

Cisco IOS XE Release 3.8

15.3(1)S

15.2(1)E

The OSPFv3 ABR Type 3 LSA Filtering feature extends the ability of an ABR that is running the OSPFv3 protocol to filter type 3 LSAs that are sent between different OSPFv3 areas. This feature allows only packets with specified prefixes to be sent from one area to another area and restricts all packets with other prefixes. This type of area filtering can be applied out of a specific OSPFv3 area, into a specific OSPFv3 area, or into and out of the same OSPFv3 areas at the same time.

Table 2. Feature Information for OSPFv3 ABR Type 3 LSA Filtering

Feature Name

Releases

Feature Information

OSPFv3 ABR Type 3 LSA Filtering

Cisco IOS XE Release 17.4

This feature was introduced.