OSPF Initial configs - bug?
It seems there are bugs in the initial configs for the OSPF labs. The loopback 0 interfaces of all routers have masks of 255.255.255.255, vs. v4 labs that are /24. This becomes an issue in the OSPF Network Loopback task. This starts in the inital ospf configs, and seems present in the ospf over broadcast media, and dmvpn configs as well. It appears to be fixed in later OSPF lab configs.