Home Router NAT Port Address Translation

A short video presentation of how most home routers do network address translation. It is useful to know how the router knows which device to send the data to. It is also helpful to understand why VPN routers need to use a different internal subnet to avoid getting confused.

Original longer video covering forms of NAT less frequently used in home routers: Youtube: NAT Explained | Overload, Dynamic & Static

Cisco Packet Tracer

Packet Tracer is a cross-platform visual simulation tool designed by Cisco Systems that allows users to create network topologies and imitate modern computer networks. The software allows users to simulate the configuration of Cisco routers and switches using a simulated command line interface. Packet Tracer makes use of a drag and drop user interface, allowing users to add and remove simulated network devices as they see fit. The software is mainly focused towards Certified Cisco Network Associate Academy students as an educational tool for helping them learn fundamental CCNA concepts. 

Packet Tracer requires authentication with your NetAcad.com login and password when you first use it and for each new OS login session.