CCNA Practice Exam Test Sample – Question 194

When a router undergoes the exchange protocol within OSPF, in what order does it pass through each state?

A. exstart state > loading state > exchange state > full state
B. exstart state > exchange state > loading state > full state
C. exstart state > full state > loading state > exchange state
D. loading state > exchange state > full state > exstart state

Correct Answer: B
Section: IP Routing Technologies

Explanation:
When OSPF adjacency is formed, a router goes through several state changes before it becomes fully adjacent with its neighbor. Those states are defined in the OSPF RFC 2328, section 10.1. The states are (in order) Down, Attempt, Init, 2-Way, Exstart, Exchange, Loading, and Full.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13685-13.html