Discuss the fact that it is important to test for invalid input for the initial sentinel value when using while loops. How might you modify the code in Examples 5-4 and 5-5 to account for an invalid initial sentinel value? In other words, you would like the condition of the while loop to be tested at least once without input failure, and you would also like to avoid an infinite loop. Would initializing the sentinel variable during its declaration be helpful?

The appropriate answer will be "Port forwarding ".

Explanation:

Port forwarding seems to be a network security strategy whereby a gateway or equivalent system communicates all intercepting communication/traffic from a specific address to some of the same port on just about any interior single node.This allows the connection of an entity in this context device that is connected to an inner reference node/port usually connecting to Internet infrastructure as well as an internal private local area network.