IP Routing: OSPF Configuration Guide, Cisco IOS Release 15S
IPv6 Routing: OSPFv3 Authentication Support with IPsec
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IPv6 Routing: OSPFv3 Authentication Support with IPsec

IPv6 Routing: OSPFv3 Authentication Support with IPsec

In order to ensure that Open Shortest Path First version 3 (OSPFv3) packets are not altered and re-sent to the device, OSPFv3 packets must be authenticated. OSPFv3 uses the IPsec secure socket API to add authentication to OSPFv3 packets. This API supports IPv6.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

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.

Prerequisites for IPv6 Routing: OSPFv3 Authentication Support with IPsec

Configure the IP Security (IPsec) secure socket application program interface (API) on OSPFv3 in order to enable authentication and encryption.

Information About IPv6 Routing: OSPFv3 Authentication Support with IPsec

OSPFv3 Authentication Support with IPsec

In order to ensure that OSPFv3 packets are not altered and re-sent to the device, causing the device to behave in a way not desired by its system administrators, OSPFv3 packets must be authenticated. OSPFv3 uses the IPsec secure socket API to add authentication to OSPFv3 packets. This API supports IPv6.

OSPFv3 requires the use of IPsec to enable authentication. Crypto images are required to use authentication, because only crypto images include the IPsec API needed for use with OSPFv3.

In OSPFv3, authentication fields have been removed from OSPFv3 packet headers. When OSPFv3 runs on IPv6, OSPFv3 requires the IPv6 authentication header (AH) or IPv6 ESP header to ensure integrity, authentication, and confidentiality of routing exchanges. IPv6 AH and ESP extension headers can be used to provide authentication and confidentiality to OSPFv3.

To use the IPsec AH, you must enable the ipv6 ospf authentication command. To use the IPsec ESP header, you must enable the ipv6 ospf encryption command. The ESP header may be applied alone or in combination with the AH, and when ESP is used, both encryption and authentication are provided. Security services can be provided between a pair of communicating hosts, between a pair of communicating security gateways, or between a security gateway and a host.

To configure IPsec, you configure a security policy, which is a combination of the security policy index (SPI) and the key (the key is used to create and validate the hash value). IPsec for OSPFv3 can be configured on an interface or on an OSPFv3 area. For higher security, you should configure a different policy on each interface configured with IPsec. If you configure IPsec for an OSPFv3 area, the policy is applied to all of the interfaces in that area, except for the interfaces that have IPsec configured directly. Once IPsec is configured for OSPFv3, IPsec is invisible to you.

The secure socket API is used by applications to secure traffic. The API needs to allow the application to open, listen, and close secure sockets. The binding between the application and the secure socket layer also allows the secure socket layer to inform the application of changes to the socket, such as connection open and close events. The secure socket API is able to identify the socket; that is, it can identify the local and remote addresses, masks, ports, and protocol that carry the traffic requiring security.

Each interface has a secure socket state, which can be one of the following:

  • NULL: Do not create a secure socket for the interface if authentication is configured for the area.
  • DOWN: IPsec has been configured for the interface (or the area that contains the interface), but OSPFv3 either has not requested IPsec to create a secure socket for this interface, or there is an error condition.
  • GOING UP: OSPFv3 has requested a secure socket from IPsec and is waiting for a CRYPTO_SS_SOCKET_UP message from IPsec.
  • UP: OSPFv3 has received a CRYPTO_SS_SOCKET_UP message from IPsec.
  • CLOSING: The secure socket for the interface has been closed. A new socket may be opened for the interface, in which case the current secure socket makes the transition to the DOWN state. Otherwise, the interface will become UNCONFIGURED.
  • UNCONFIGURED: Authentication is not configured on the interface.

OSPFv3 will not send or accept packets while in the DOWN state.

How to Configure IPv6 Routing: OSPFv3 Authentication Support with IPsec

Configuring IPsec on OSPFv3

Once you have configured OSPFv3 and decided on your authentication, you must define the security policy on each of the devices within the group. The security policy consists of the combination of the key and the SPI. To define a security policy, you must define an SPI and a key.

You can configure an authentication or encryption policy either on an interface or for an OSPFv3 area. When you configure for an area, the security policy is applied to all of the interfaces in the area. For higher security, use a different policy on each interface.

You can configure authentication and encryption on virtual links.

Defining Authentication on an Interface

Before You Begin

Before you configure IPsec on an interface, you must configure OSPFv3 on that interface.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    interface type number

    4.    Do one of the following:

    • ospfv3 authentication {ipsec spi} {md5 | sha1}{ key-encryption-type key} | null
    • ipv6 ospf authentication {null | ipsec spi spi authentication-algorithm [key-encryption-type] [key]}


DETAILED STEPS
     Command or ActionPurpose
    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 interface type number


    Example:
    Device(config)# interface ethernet 0/0
    
     

    Specifies an interface type and number, and places the device in interface configuration mode.

     
    Step 4Do one of the following:
    • ospfv3 authentication {ipsec spi} {md5 | sha1}{ key-encryption-type key} | null
    • ipv6 ospf authentication {null | ipsec spi spi authentication-algorithm [key-encryption-type] [key]}


    Example:
    Device(config-if)# ospfv3 authentication md5 0 27576134094768132473302031209727
    


    Example:

    Or

    Device(config-if)# ipv6 ospf authentication ipsec spi 500 md5 1234567890abcdef1234567890abcdef
    
     

    Specifies the authentication type for an interface.

     

    Defining Authentication in an OSPFv3 Area

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ipv6 router ospf process-id

      4.    area area-id authentication ipsec spi spi authentication-algorithm [key-encryption-type] key


    DETAILED STEPS
       Command or ActionPurpose
      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 ipv6 router ospf process-id


      Example:
      Device(config)# ipv6 router ospf 1
      
       

      Enables OSPFv3 router configuration mode.

       
      Step 4 area area-id authentication ipsec spi spi authentication-algorithm [key-encryption-type] key


      Example:
      Device(config-rtr)# area 1 authentication ipsec spi 678 md5 1234567890ABCDEF1234567890ABCDEF
      
       

      Enables authentication in an OSPFv3 area.

       

      Configuration Examples for IPv6 Routing: OSPFv3 Authentication Support with IPsec

      Example: Defining Authentication on an Interface

      The following example shows how to define authentication on Ethernet interface 0/0:

      interface Ethernet0/0
       ipv6 enable
       ipv6 ospf 1 area 0
       ipv6 ospf authentication ipsec spi 500 md5 1234567890ABCDEF1234567890ABCDEF
      interface Ethernet0/0
       ipv6 enable
       ipv6 ospf authentication null
       ipv6 ospf 1 area 0

      Example: Defining Authentication in an OSPFv3 Area

      The following example shows how to define authentication on OSPFv3 area 0:

      ipv6 router ospf 1
       router-id 10.11.11.1
       area 0 authentication ipsec spi 1000 md5 1234567890ABCDEF1234567890ABCDEF

      Additional References

      Related Documents

      Related Topic

      Document Title

      IPv6 addressing and connectivity

      IPv6 Configuration Guide

      Cisco IOS commands

      Cisco IOS Master Commands List, All Releases

      IPv6 commands

      Cisco IOS IPv6 Command Reference

      Cisco IOS IPv6 features

      Cisco IOS IPv6 Feature Mapping

      IPv6 Routing: OSPF for IPv6 Authentication Support with IPsec

      Configuring OSPF ” module

      Standards and RFCs

      Standard/RFC

      Title

      RFCs for IPv6

      IPv6 RFCs

      MIBs

      MIB

      MIBs Link

      To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

      http:/​/​www.cisco.com/​go/​mibs

      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 IPv6 Routing: OSPFv3 Authentication Support with IPsec

      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 IPv6 Routing: OSPF for IPv6 Authentication Support with IPsec

      Feature Name

      Releases

      Feature Information

      IPv6 Routing: OSPF for IPv6 Authentication Support with IPsec

      12.3(4)T

      12.4

      15.0(2)SE

      15.1(1)SY

      15.2(1)S

      OSPFv3 uses the IPsec secure socket API to add authentication to OSPFv3 packets.

      The following commands were introduced or modified: area authentication (IPv6), ipv6 ospf authentication, ipv6 router ospf, ospfv3 authentication.