@O'Niel - how much do you know about NAT and routing and networking protocols

Not much. I guess I have to do port-forwarding, but yet I'm not sure.

I know the theory about protocols though (TCP vs UDP etc.)

I know how they travel from start-point to end-point.

But I'm nothing close to a network-administrator.

So as regards routing between networks you'll want to study NAT and routing protocols. Worth having a look at how routers may also have ACL's applied to prevent connections.

Worth first ensuring you can do the basics - can you ping between all the machines you want to communicate?

I solved my question, I just had to port-forward. @RoryAlsop: Thanks for the tip, yeah I can ping all the machines between me and my endpoint, ain't this also automatically done when you do traceroute?

Yep - I was going to start at ICMP and work up - wasn't sure from your question what layers you were aware of

@O'Niel for beef (and metasploit, with reverse shells anyway) the key is that the target machine needs to be able to contact the system running beef or metasploit at a network level

so if your "target" is on another network, they need to have a route back to yours.

In general the easiest way to handle this is to place the beef/metasploit servers on a machine with an Internet facing IP address, as most clients have Internet access

However with this you then have to be very careful of the security of that host as you're essentially exposing it to the Internet with no firewall

so it's easily compromised

a good way to get started with something like that would be to rent a VM from somewhere like digital Ocean

which will give you an Internet facing IP address

and then just use it for your testing. That way if this machine is attacked it's less likely you'll have anything sensitive on it.

@RoryAlsop ICMP, ain't that just the "Error checker" of your routing-steps to your endpoint? Like if a specific step ain't working because of e.g a config-failure it'll tell you? @RоryMcCune Thanks for your explanation and tip, I'll use it.

Very much - it's pretty much the base layer that lets you spot basic routing issues.

@RoryAlsop Actually, I do have a question about protocols. Each protocol is actually just build onto sockets, right? The only thing the very basic sockets do is sending 'strings' from point A to B.

What protocols do, is then interpret that string it the way it's mechanism is build for it. Like e.g: For sending a HTTP-request, you need to make a request-string 'GET / HTTP/1.1\r\nHost: www.example.com ...'. The mechanism at point B (the web-server actually) just interprets that string and displays the page requested etc. Right?

Well, not entirely. Protocols can sit at various layers, but you have the right principle: each layer is supposed to be independent of the layer below.

On your physical interface you are seeing electrons or photons

Higher up you have 1's and 0's.

These may be then read as strings, but may not be

But yes, an http server does just take the request, interpret it and deliver back the requested data