IPv4 Support in OSPFv3
RFC 5838 specifies that OSPFv3 should support multiple address families by setting the instance ID value from the IPv6 reserved range to the IPv4 reserved range (64 to 95) in the link LSAs.
Enabling IPv4 support for OSPFv3 is straightforward:
Step 1. Ensure that the IPv4 interface has an IPv6 address (global or link local) configured. Remember that configuring a global address also places a link-local address; alternatively, a link-local address can statically be configured.
Step 2. Enable the OSPFv3 process for IPv4 on the interface with the command ospfv3 process-id ipv4 area area-id.
Using the topology shown in Figure 10-1, IPv4 addressing has been placed onto R1, R2, R3, and R4 using the conventions outlined earlier. Example 10-14 demonstrates the deployment of IPv4 using the existing OSPFv3 deployment.
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Example 10-14 Configuration Changes for IPv4 Support
Example 10-15 verifies that the routes were exchanged and installed into the IPv4 RIB.
Example 10-15 Verifying IPv4 Route Exchange with OSPFv3
The command show ospfv3 interface [brief] displays the address families enabled on an interface. When IPv4 and IPv6 are both configured on an interface, an entry appears for each address family. Example 10-16 lists the interfaces and associated address families.
Example 10-16 Listing of OSPFv3 Interfaces and Their Address Families
Example 10-17 shows how to view the OSPFv3 neighbors to display the neighbors enabled for IPv4 and IPv6 as separate entities.