Explain when is the subnet mask displayed with the parent route and when is the subnet mask displays with the child route and not the parent route? Elaborate your answer with examples.

22. A datagram subnet allows routers to drop packets whenever they need to. The probability of a router discarding a packet is p. Consider the case of a source host connected to the source router, which is connected to the destination router, and then to the destination host. If either of the routers discards a packet, the source host eventually times out and tries again. If both host-router and router-router lines are counted as hops, what is the mean number of a. (a) hops a packet makes per transmission? b. (b) transmissions a packet makes? (c) hops required per received packet?