• RFC 5340 – OSPF for IPv6
  • Transport via protocol 89 to unicast and multicasts FF02::5/FF02::6
  • Normal OSPF rules apply
    • Adjacency parameters same
    • OSPFv3 network types same
  • LSAs
    • Two new
      • type 8 (Link) – Used for link local
      • type 9 (Intra Area Prefix) – Used for prefixes on the link
    • Type 8 and 9 separate topology from NLRI
      • v2 has subnet info in LSAs 1 and 2 for Intra
        • if prefix add or remove, run full SPF.
      • v3 uses LSAs 8 and 9 to reference LSA 1
        • If stub network is add or remove, full SPF not required.
  • Configuration
    • Enabled at link level.
      • ‘ipv6 ospf <process id> area <area id>’
      • Automatically enables global process
    • Like EIGRPv6 and BGP, requires IPv4 router id.

The topology above is running DMVPN and we’ll enable OSPFv3. R10 is a normal OSPF broadcast link, and the tunnel interfaces on R1-3 are point to point. R5’s tunnel interface is point-to-multipoint.

On the hub the below commands will be added to the interfaces:

On the DMVPN Tunnel interface the link OSPF command is entered, the network type is changed to point-to-multipoint, and the hello interval is now 10. The timer is changed due to the spokes being point to point.

On the hub’s normal broadcast interface it will receive the normal ipv6 ospf command. This is the same for our normal non-DMVPN router hanging off of R5.

On our spokes each router will enter the following:

Just the normal ospf area 0 command. The timers do not need to be adjusted because the timers already were on the hub. The default OSPF network type on a tunnel interface is point to point, which matches what was changed on the hub.

Notice that on the Hub’s adjacency list, all the neighbors have IPv4 router IDs.

In fact, when trying to form adjacency with the normal router R4, a router ID was manually added to the OSPF process because R4 is only running IP protocol version 6.

OSPFv3 Authentication:

  • Version 3 uses IPSEC for
    • Authentication
      • IPSEC AH or ESP
    • Encryption
      • IPSEC ESP
  • No ISAKMP support, keys manually entered.

Below is an example of the configuration needed on OSPF neighbor interfaces:

This would need to be applied to all tunnel interfaces in the DMVPN topology, as well as the interface connecting R5 to R10.

The long string of numbers and letters are the key that needs to match on both sides of the neighbor relationship. This configuration was found under the Cisco OSPF docs.

Multiprotocol OSPFv3:

  • Can advertise both IPv4 and IPv6.
    • Two separate trees.
      • Each IP protocol runs independently.
    • To advertise IPv4 NLRI, must have both IPv4 and IPv6 on the link.
      • ‘ipv6 enable’ on transit links is min required for v6.
      • For IPv4 – can have all links unnumbered to Loopback interface.
  • Configuration
    • Enable on link
      • ‘ospfv3 <pid> <ipv4|ipv6> area <area #>
    • Options under OSPFv3 routing process.
      • ‘router ospfv3 <pid>’
    • show commands
      • ‘show ospfv3’

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