How can I access a computer which doesn't have unique IP?

If a target computer doesn't have it's own IP, but is using IP encapsulation (tunnelling), how can I make a connection to it, by being the one who initiates the connection?

1. Can I make such a connection with my own program? That is, is it possible to make a program that makes a connection to a computer if its inner and outer IP is known?

2. Are there any file transfer programs made that can make such a connection?

P.S. If everything I've written doesn't make any sense, please explain, what all the terms mean...

If a target computer doesn't have it's own IP, but is using IP encapsulation (tunnelling), how can I make a connection to it, by being the one who initiates the connection?

1. Can I make such a connection with my own program? That is, is it possible to make a program that makes a connection to a computer if its inner and outer IP is known?

2. Are there any file transfer programs made that can make such a connection?

P.S. If everything I've written doesn't make any sense, please explain, what all the terms mean...

--What are your intentions of making a connection with a *target Computer* or Is it just you are exploring your own test network? Looks suspicious to me.

Are you asking *US* to explain what you wrote?

If a target computer doesn't have it's own IP, but is using IP encapsulation (tunnelling), how can I make a connection to it, by being the one who initiates the connection?

1. Can I make such a connection with my own program? That is, is it possible to make a program that makes a connection to a computer if its inner and outer IP is known?

2. Are there any file transfer programs made that can make such a connection?

P.S. If everything I've written doesn't make any sense, please explain, what all the terms mean...

--What are your intentions of making a connection with a *target Computer* or Is it just you are exploring your own test network? Looks suspicious to me.

Are you asking *US* to explain what you wrote?

You are too suspicious. :lol: I need to transfer files from the computer that does not have it's own IP (for all the network's computers outer IP is the same in that network) to another computer that has the same problem. I searched for FTP Server-Client, that would allow such a connection to be established with no results. All I tried to ask is, if it is possible to make one myself...

So, what you are trying to do is access a private intranet that is sealed off by means of a firewall/nat or proxy.. correct? As long as you are trusted to the border security device, whether it be a firewall or proxy server you should have no problems iniating a connection with a computer in the private intranet. If you have not set up the border security device to allow that sort of traffic, get in contact with whoever is in charge with the device to set up some sort of method for you to gain remote access. As for doing it without permission, I'd rather not discuss such a method :roll:

Edg,

Sounds like your simply trying to access a PC which is located at the other end of the tunnel. If this is so, then all you'll require is to somehow 'guide' your PC to the other end.

Usually, this is something done at the gateway level, where connections from WAN networks arrive and it then has the task to correctly route packets between them. By entering your default gateway at your workstation, and assuming the gateway has been updated with the new tunneled network's IP addressing scheme (that's in the case no routing protocols are being used), then you should be able to get to it - if you have access.

Should the gateway be totally unaware of this remote network, then all you need is to create a new route entry in your workstation, telling it ' To get to network A.B.C.D, go through IP Address E.F.G.H'

The 'E.F.G.H' address is usually a router or some type of gateway that will automatically encapsulate your packet and send it through the tunnel to the other end.

The most simple form of encapsulation with Cisco router's is GRE (Generic Routing Encapsulation) - which of course is also covered in our upcoming Cisco lab !

Well if you're talking about bypassing a Natting system, this is a bit complex.. the correct way would be to use port forwarding, where a 'live' system will forward one port to a target port on the internal box... in short some kind of proxying system..

There is another way.. since you're talking about implementing it yourself, this shouldnt be too hard, buts its a little home-grown..

Setup some publicly accessible page.. for example a geocities page.. and have a program on the internal box routinely query that page.. say if the page says '1' it should know to initiate a connection to a predetermined IP.. or you could pass the IP through the page..

While you may say this is not you initiating the connection.. it 'technically' is.. since you modify the content of the page when you want to have the connection made.


I know, this may sound random, but there are actually interesting uses for this.