Which two statements describe the process identifier that is used in the command to configure OSPF
on a router? (Choose two.)
Router(config)# router ospf 1

A.
All OSPF routers in an area must have the same process ID.

B.
Only one process number can be used on the same router.

C.
Different process identifiers can be used to run multiple OSPF processes

D.
The process number can be any number from 1 to 65,535.

E.
Hello packets are sent to each neighbor to determine the processor identifier.

Explanation:
we all know that The areas can be any number from 0 to 4.2 billion and 1 to 65,535 for the Process
ID. The process ID is the ID of the OSPF process to which the interface belongs. The process ID is
local to the router, and two OSPF neighboring routers can have different OSPF process IDs. (This is
not true of Enhanced Interior Gateway Routing Protocol [EIGRP], in which the routers need to be in
the same autonomous system). Cisco IOS Software can run multiple OSPF processes on the same
router, and the process ID merely distinguishes one process from the another. The process ID should
be a positive integer.