Does Ohphonex Work When Behind A Nat?
If it begins with '192.168', as mine does, then you are almost certainly behind a NAT router. IP addresses that begin with '192.168' are actually invalid on the internet as they are specifically intended for non-internet, local networks. After a while of searching I do not find a suitable solution. Following setup: Office PC (linux, root access) behind NAT (IP not public) but full Internet access. Server PC (linux, no root access) static and public IP and full Internet access. Home PC (linux, root access).
We have an IP address on the global internet: 'A' We only have access to 'A'. We have a network behind a router that does NAT: 192.168.1.0/24 There is a client behind that NAT: 'B' We don't have access to 'B' and the 'NAT' router. Goal: reach the 'B' directly with 'A'. We cannot use port forwarding or UPnP, etc. Question: what is the trick to reach 'B'?
Does Iphone Work When Behind A Nat Device
A trick that could be avoided if the router had a stateful firewall, not just NAT! We are thinking that when 'B' browses the web, it will go out to the internet. When it is receiving replies, the router that does the NAT needs to decide which NATed IP did 'B' have?
(there could be more machines behind the NATed network). For this the NAT router uses the port information too.
Maybe if we/they are using UDP, we can try all non-privileged ports with the IP 'A' to send a packet to 'B'? The NAT router is just a simply soho router. (original problem: trying to prove that NAT is not a firewall, but we need an evidence for it). Actually, your plan could work, depending on how the NAT device works. Typically, NAT devices map the internal IP and source port to the destination IP and port so that it only allows that IP and port to communicate back to the internal IP. This makes NAT a very crude and poor stateful firewall. But this function is not a mandated part of NAT, which means any vendor can choose to implement this approach, or not.
Does Ohphonex Work When Behind A Nat Type
That means that it is theoretically possible to be able to scan a NAT device's ports and discover the internal network if the devices on the internal network respond to connection attempts. That's a big series of 'ifs'. But worthwhile.
So, yes, NAT alone is insufficient, because you do not know how NAT was implemented. A stateful firewall provides defence-in-depth to cover this potential unknown hole. NAT is not a security technology and should not be treated as a protection mechanism.
The scenario is the following. I have two machines A and B: A: Client (behind NAT) B: Server (behind NAT) I want B to be able to listen on any given port, so that A can send packets to B through that specific TCP port and receive any response. If both machines are not behind a NAT it is pretty straight foward process. However how do I make it work so that it works even when B is behind a router, without him having to go change the router configuration enable some port forwarding etc. For example, how do peer-to-peer programs like torrent clients work without the user having anything to configure? An alternative to a proxy server is a match-making server.
Instead of proxying all of the traffic, the match maker just negotiates until the peers can talk to each other. This involves finding the external public IPs of the peers and talking to each one so that the firewall/router knows that the peers wish to communicate. This is called and it often has to be done by the match maker rather than the peers themselves. Once the hole are punched though, the match maker can tell the peers about each other and they can communicate directly.