The packet is
dropped or discarded. By default, a router will send packets
to a network that has been listed in the routing table. If it happens that the
network is not listed, the packet will be discarded or dropped. Packets that do
not have a default route or gateway of last resort are dropped.
The answer is one ☝️ question for the poll of a vote
Layer 3, the Network Layer, just like the OSI model.
The answer is : Ergonomics
. It is about ensuring that the work system is favorable to good performance and work effectiveness and consequently, that the work environment is compatible with the health, safety and comfort of the worker. It reduces hazards in the working environment.