Which of the following describe the process identifier that is used to run OSPF on a router?<br>1. It is locally significant.<br>2. It is globally significant.<br>3. It is needed to identify a unique instance of an OSPF database.<br>4. It is an optional parameter required only if multiple OSPF processes are running on the router.<br>

Correct Answer: 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.