Which of the following describe the process identifier that is used to run OSPF on a router?

1. It is locally significant.
2. It is globally significant.
3. It is needed to identify a unique instance of an OSPF database.
4. It is an optional parameter required only if multiple OSPF processes are running on the router.

ANS:B - 1 and 3

The Process ID for OSPF on a router is only locally significant and you can use the same number on each router, or each router can have a different number-it just doesn't matter. The numbers you can use are from 1 to 65,535. Don't get this confused with area numbers, which can be from 0 to 4.2 billion.