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Same private network on each side of a VPN. It's posible?

Posted: Tue May 25, 2010 1:26 pm
by Ibersystems
Hello,

I want to make a PPTP or L2TP VPN between 4 hotels and I want to keep the private network with 192.168.1.0/24 in all the hotels.

Can I make it?

The reason is that our ISP has the default IP address 192.168.1.1, and we need that if they change one router because is dead.. we don't need to change nothing in this router configuration to give connectivity to all computers and work via VPN.

There is something like address translation? I would have a routeros on each side with static public IP in the ADSL router, directly connected to my routeros.


Thanks,

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 3:17 pm
by JorgeAmaral
Hi Martin,

You need proxy-arp.

Kindly regards,

Jorge

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 5:05 pm
by Ibersystems
Hi,

If I have 192.168.1.34 in the hotel1 and the same IP in the hotel2, I will have problems? It's what I need.. Try to avoid make changes there.. I want to know if I can create a "virtual" IP ranges without change the real private IPs.

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 5:49 pm
by -headstrong-
Create a masquerade rule, out the VPN interface, but with the source IP of 192.168.1.34.....?

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 6:25 pm
by Ibersystems
Must use masquerade 192.168.1.0/24.

This will work? I didn't make something like this.. never..

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 8:21 pm
by -headstrong-
Well what are your routing requirements?

Does 192.168.1.34 at hotel 1 need to access 192.168.1.34 at hotel 2? That will be an issue..

You could create a "virtual" ip range and do port forwarding at each router...eg

private IP: 192.168.1.34

Hotel1: lobridge IP 192.168.2.34 but DNAT to 192.168.1.34
Hotel2: lobridge IP 192.168.3.34 but DNAT to 192.168.1.34
Hotel3: lobridge IP 192.168.4.34 but DNAT to 192.168.1.34
Hotel4: lobridge IP 192.168.5.34 but DNAT to 192.168.1.34

Then 192.168.1.34 at hotel1 can access 192.168.1.34 at hotel2. Hotel1 would ping 192.168.3.34 which would ping 192.168.1.34 at hotel2

Make sense? Not sure if the above will work tho

Re: Same private network on each side of a VPN. It's posible

Posted: Tue May 25, 2010 8:23 pm
by -headstrong-
proxy arp might do the trick tho, depending on your needs