This is from Wendell Odom's book:
An enterprise uses a dual-stack model of deployment for IPv4 and IPv6, using OSPF as the routing protocol for both. Router R1 has IPv4 and IPv6 addresses on its G0/0 and S0/0/0 interfaces only, with OSPFv2 and OSPFv3 enabled on both interfaces for area 0 and the router ID explicitly set for both protocols. Comparing the OSPFv2 and OSPFv3 configuration, which of the following statements is true?
a. The OSPFv3 configuration, but not OSPFv2, uses the router-id router-id router subcommand.
b. Both protocols use the router-id router-id router subcommand.
c. Both protocols use the network network-number wildcard area area-id router subcommand.
d. The both protocols use the ipv6 ospf process-id area area-id interface subcommand
Answer is B
Answering this question I could easily eliminate options A and D but why is B the only answer in this scenario? I cannot figure it out for OSPFv2 does utilize option C which I researched in Odom's same (for the OSPFv2 Chapter) book stated here in step 3:
brief reference to the required commands:
Step 1. Enter OSPF configuration mode for a particular OSPF process using the router ospf process-id global command.
Step 2. (Optional) Configure the OSPF router ID by:
A. Configuring the router-id id-value router subcommand
B. Configuring an IP address on a loopback interface
Step 3. Configure one or more network ip-address wildcard-mask area area-id router subcommands, with any matched interfaces being added to the listed area.
Clarification on this question is greatly appreciated!
