Event-driven updates are a much more sophisticated means of
initiating routing updates. Ostensibly, an update is initiated only when
a change in the network's topology has been detected.
Given that a
topology change is what creates the need for convergence, this approach
is obviously the more efficient one. An example of this is the OSPF
routing protocol.
You can select an update initiator just by selecting a routing
protocol; each protocol implements either one or the other. Therefore,
this is one factor that must be considered when selecting a routing
protocol