Feature #9: Update Configuration

Description

We have a network topology in which several network routers are interconnected in a rectangular grid. A router has four neighboring routers: $up,\ right,\ left,$ and $down$. A router transmits a configuration update control message to its 4 directionally adjacent neighbors in response to a configuration change. The routers exchange control messages with their adjacent neighbors at one-minute intervals.

A router accepts the configuration change only if it receives a configuration update from its four neighbors, ...