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I have two ADSL connections. Every one of them have 8 valid IP numbers. Everyone has an ADSL router. Is there a way, other than VPN (slow connections) to:

  • Let computers behind routers see each other belonging to a common, not valid IP network segment (i.e.
  • Put sensitive information servers behind routers so they be can be seen only from
  • Other common network services

Thanks in advance!

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wow - – Chopper3 Oct 21 '10 at 13:13
I'm kind of confused... – Bart Silverstrim Oct 21 '10 at 13:15
What exactly is the OP trying to actually accomplish? Tying the two together for increased speed? Are these at two different sites and he wants to link the two sites together? What does the 8 IP numbers on each ADSL connections mean? – Bart Silverstrim Oct 21 '10 at 13:18
I have two networks, I would like to share files, printers and network services in general. I mean 8 real IP numbers that I can use on each ADSL. – Ramon Araujo Oct 21 '10 at 13:49
up vote 1 down vote accepted

What (I think) you're describing is a site-to-site routed WAN topology that's common for connecting branch offices together, but almost always uses some form of VPN, most common being IPSec.

Encryption does add some overhead, but there's really no other way of getting around the insecurity of a public Internet connection without the benefit of encryption and authentication that a VPN provides for you.

You can talk to your ISP and have them setup LAN extensions for you, but they're going to be much more than your ADSL connections if price is a concern and may not be available as an option.

I say give the VPN a try: if your router/firewalls are not VPN capable, you can setup asynchronous OpenVPN tunnels on a spare workstation running Linux/BSD, etc. at both locations; these new OpenVPN servers will maintain the VPN tunnel and route traffic between both locations.

You'll have to setup static routes at each locations' default gateway (ADSL router, hopefully you can do that) to route traffic destined for the other location's local subnet to the local OpenVPN server (which is acting as a router now).

See this section at OpenVPN for more information:


Playing the guessing game here, but after re-reading your question, it sounds like you want the network to span across WAN connections and the only way to do this would be to bridge it. OpenVPN can do this, but I don't think that's what you want, especially if bandwidth is a concern as you'd be on one big broadcast domain. Much better idea would be to route only the traffic you need across the tunnel.

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You will need to use tunneling and/or some sort of private network provided by an isp. Since you have not opted to upgrade your wan link I assume money is an issue, so the only way I can tihnk to achieve this is to use pptp without encryption to reduce overhead.

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Are these ADSL connections in the same location? If so, it's relatively easy, just stick everything behind a (sufficiently intelligent) firewall, on a single ethernet broadcast domain (essentially, hook everything into one or more switches).

If you're looking at multiple connections, the only way of doing it would be with some sort of VPN solution. I'd use two sub-blocks from 10/8, 172.16/12 or 192.168/16 and route between them. Probably easiest to have some sort of firewall doing double duty as NAT device and VPN gateway at each site.

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