Holest Engineering Information

NAT devices (routers) enable multiple devices in local network to share single IP making internet easily distributable to any computer/device in home or office network. NAT also provides basic shield to local network form possible outside attacks, because they don't let any traffic form outside reach computer/device on local network unless device/computer in local network initiates connection by sending request to remote service. NAT keep records of requests and lets back data from remote service only if local client has initiated data transfer. Routers commonly also have built in firewall that further increases security protection by router device. This is great, but what about End-To-End connectivity. Original concepts had flaws to use it without consequences but no dough we need it and it's irreplaceable for some sorts of communication.