What is the effect when loopback interfaces and the configured router ID are absent during the OSPF Process configuration?
What is the effect when loopback interfaces and the configured router ID are absent during the OSPF Process configuration?
When loopback interfaces and a configured router ID are absent during the OSPF process configuration, the highest IP address on any of the router's physical interfaces is selected as the router ID. This can include interfaces that might not necessarily be in an up/up state at the moment of OSPF process initialization.
D: is the correct one "The highest up/up physical interface IP address is selected as the router ID."
I guess its D coz the highest physical int. address comes next. Im concerned about this answer coz in my knowledge it does not need to be UP/UP. It just have to exist.
For OSPF to use an interface to determine the router ID, the interface does not have to be in the UP/UP state. It can be in a DOWN/DOWN state. The router ID is selected based on the highest IP address of any of the router's active interfaces (including loopback interfaces) at the time of OSPF process startup. If no loopback interfaces are configured, OSPF will use the highest IP address on any physical interface, even if that interface is currently down. Screw you CCNA :)
actually correct answer is poorly worded. interface could be in state UP/DOWN and still be eligible for being router ID.