OSPF carries more overhead than other routing protocols (such as EIGRP) because of its periodic and indefinite need to refresh LSAs every 30 minutes (1800 seconds).
When you issue a show ip ospf database to view the LSAs within the AS, check the Age value next to the database entries for the value, which counts up from zero to 1800 seconds in a normal network environment. When the 30 minute threshold is reached, it performs the LSA refresh, floods update packets and increments its sequence number, located in the Seq# column.
Each LSA update increments the sequence number by 1.
Eventually, a route will run out of sequence numbers because this process is performed indefinitely. It therefore needs to reset the route among all neighbors, so it effectively sends a route refresh message with the max age value of 60 minutes (3600 seconds) which essentially poisons the route and resets the sequence number back to zero.
You will likely not see an age greater than 1800 seconds under normal and stable network conditions.
Stuck-in-Active: Journal of an IT-Network Administrator 