The metrics can be calculated using a simple algorithm. Entity i gets its neighbor k to send their estimates of their distance from j . Then i picks the smallest value. Very few assumption were made about the order in which the entities send each other their information. That means that it is safe to run the algorithm asynchronously.
Entities can send updates by their own clock.
Updates may be dropped, as long as they don't get all dropped. Because there are no assumptions on the initials values, the algorithm handles changes. Once a router is installed, or started, it should send messages to all of its neighbors. This is necessary in order to update their tables. A was connected to D through B and C .