This object reports how many seconds have elapsed since this specific link-state advertisement was originated or last refreshed, which in OSPF counts up toward MaxAge, typically 3600 seconds or one hour, at which point the LSA is flushed from the database if not refreshed. It matters because an LSA's age climbing continuously without resetting back to a low value indicates its originating router has stopped refreshing it, often a sign that router has gone down or lost connectivity, and the LSA is heading toward automatic expiration. An admin seeing a specific router's LSAs consistently aging past several minutes without refreshing back to near-zero should suspect that router is having trouble, even before it fully times out.