This read-create Unsigned32, in seconds, sets how often DVMRP Report messages describing this router's known source networks are sent out the interface, with 0 disabling periodic Reports. An admin adjusts it to control how quickly downstream routers learn about routing changes versus how much periodic control traffic the link carries. For example, shortening the default 60-second interval on a link prone to route flapping would let neighbors reconverge faster after a topology change.