Help with multiple routers

[PhilTilson]

Hi -

I live in rural Spain and my internet connection is provided via a wireless link. The hub at the centre of this network has a fixed IP address and distributes the internet via a router on a sub-network. So far, so good!

I receive this and feed it into my own router for my local network. I now want to access my PCs from the UK when I am there. I vaguely understand the principle of opening ports on my router to allow external access to my network, but how can I do this through two levels? I'm not sure I can get my service provider to fiddle with the router at his end, so am I completely stuffed, or is there a way round this?

Assuming he is cooperative, what do I need to ask him to do to facilitate this external access, and what do I need to do at my end? Fairly low-level replies would be appreciated!!

Thanks

[johnwill]

I really doubt you can open ports on the ISP's router that you don't have access to. I can't imagine them doing custom configurations for each client on that network!

I'd consider something along the lines of Hamachi to provide the access.

[PhilTilson]

Originally Posted by johnwill

I really doubt you can open ports on the ISP's router that you don't have access to. I can't imagine them doing custom configurations for each client on that network!

Under normal circumstances you'd be right, but this network was actually set up by a friend, and I could probably get him to make some changes if I knew what to ask for! The problem is, I'm not sure what would be required in order to get a 'double-hop' across the two routers.

I'd consider something along the lines of Hamachi to provide the access.

I did try downloading Hamachi once in order to try to get my HP iPAQ talking to my other computers, but failed dismally!

[asgley]

Hi,

First you need to know what you are trying to acheive, there are many ways to remote access your machine, even if your ISP blocks all inbound ports it can still be done.
I will assume at this point you wish to 'VNC' to your machine, Tight VNC is a neat little application that allows access to your machine with a password and can easily be run an any port you like.

Now from how I understood your post this is the current layout.
NET
|-- ISP Router
**|--Wireless Private Network (10.*, 172.16-31.*, 192.168.*)
****|-- Phil's Router
******|-- Phil's Computers (10.*, 172.16-31.*, 192.168.*)

In this case all people using the same Wireless network will share the same external IP (www.whatismyip.com)
This does however pose an interesting security problem, if you were to use RDP (3389) then you could have loads of people trying to log into your machine thinking its theirs, as I have had issues running XP's RDP through a translated port in the past another application as suggested above would probably be advised.
I will point out that Tight VNC doesn’t currently support encryption though it is planned, you can run it over a SSH tunnel to encrypt the data stream.

Anyway,
Get your ISP to assign you a static IP on their network.
Choose a port (1024-64999) I would suggest something over 10,000 which isn't a 'known' port.
Get your ISP to forward the port on the external address to your Wireless static IP.
Forward the same port on your router to your computer, which of course has a different network address.
Open the port on your computer.
Check connectivity locally.
Check connectivity from the wireless network.
Check connectivity from the WWW.


Hope it helps even just a bit.

Asg

[PhilTilson]

Originally Posted by asgley

Now from how I understood your post this is the current layout.
NET
|-- ISP Router
**|--Wireless Private Network (10.*, 172.16-31.*, 192.168.*)
****|-- Phil's Router
******|-- Phil's Computers (10.*, 172.16-31.*, 192.168.*)

On the nail!

Get your ISP to assign you a static IP on their network.
Choose a port (1024-64999) I would suggest something over 10,000 which isn't a 'known' port.
Get your ISP to forward the port on the external address to your Wireless static IP.
Forward the same port on your router to your computer, which of course has a different network address.
Open the port on your computer.
Check connectivity locally.
Check connectivity from the wireless network.
Check connectivity from the WWW.

I should be able to manage all that!

Hope it helps even just a bit.

Asg

That helps A LOT, Asg - thanks!

Phil

[PhilTilson]

Just another quick question, Asg -

I assume that to connect to my local computer from elsewhere, I need to use the URL: http://123.45.678.90:12345 where 123.45.678.90 is the external address of my ISP's router and 12345 is the port number that I have enabled?

As my 'ISP' is actually a friend locally who is providing wireless internet access to a large number of people (it's a long story!) I am assuming that his external IP address is not registered on a DNS somewhere, so not accessible by name.

Am I on the right lines?

Incidentally, I have downloaded and installed TightVNC and tested it locally and it is brilliant! I have looked at VNC offerings before but they always seemed too damned complicated. This was very straightforward.

Thanks again.

Phil

[asgley]

Hi Phil,

You will need to use the external address of your ISP with the port, though you dont have to remember the IP, check out http://www.no-ip.com/
This will allow you to set an easy to remember name against the IP you wish to connect to.

the Http:// part is down to how you decide you want to use VNC, if you just want to connect to the main port then you will need to download and install the tight vnc client on the remote pc's, if you use the web service i believe you may need to open up two ports, but i havent used vnc in a few years so i cant be 100% on this.

I would just point out if this wireless network is part of a widespread project then its entirely possible they have routers infront of the "external" one and they may block traffic at a higher level so all these changes may not actually work anyway.

I'm glad you like VNC, its saved my *** a few times

Asg