Even though OSPF is the most popular interior gateway protocol, the best practices and common deployment limits how we use the protocol. Due to this practice in the industry, the less obvious features may be ignored; therefore CCIE Routing and Switching candidates are missing points on those features. This document is to cover the general operation of OSPFv2 & OSPFv3 and how they may be used within the CCIE R&S practical exam. The goal is to give the candidate an understanding of how OSPFv2 & OSPFv3 works and how they may be used within the CCIE R&S practical exam and therefore will help shorten the time spent configuring and troubleshooting OSPFv2 & OSPFv3 within the exam.