How to disguise external traffic as internal traffic?

Question

Computer networks

Hello
Is it possible to somehow disguise external traffic as internal?

Answer 1

In the general case, there is no way, since usually the traffic is counted literally from the outside (in the node between the internal network and the external one) and this cannot be bypassed.
But in some rare cases, you can find a type of traffic that is not tracked, for example, I remember a dns proxy that, using this type of data, allowed you to connect to your server from the outside and access the Internet through it (I was told this way providers in the 'run out of money' mode and only the internal sites of the provider and its dns were available, they robbed).
Of the untracked traffic, you can still recall ping icmp, there were proxy based on receiving / transmitting mail messages, and now you can almost certainly file one based on chat applications.

Answer 2

Maybe you can, it all depends on where, how, why. And so the question is from the category "is it possible to pass off a crocodile as a bird" :)