13.7. Receiving link state acknowledgments

Many consistency checks have been made on a received Link State Acknowledgment packet before it is handed to the flooding procedure. In particular, it has been associated with a particular neighbor. If this neighbor is in a lesser state than Exchange, the Link State Acknowledgment packet is discarded.

Otherwise, for each acknowledgment in the Link State Acknowledgment packet, the following steps are performed:

• Does the advertisement acknowledged have an instance on the Link state retransmission list for the neighbor? If not, examine the next acknowledgment. Otherwise:

• If the acknowledgment is for the same instance that is contained on the list, remove the item from the list and examine the next acknowledgment. Otherwise:

• Log the questionable acknowledgment, and examine the next one.