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Does there exist a router that supports multiple GRE connections over NAT? Im currently running pfSense, and it only supports 1 at a time. I understand why, its just a drag as there are multiple people in this office trying connect to the same VPN server.

Obviously there are other ways to solve this, like different VPN setups, multiple interfaces, etc, but for a variety of reasons Id much prefer multiple GRE connections.

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Is your VPN is pure GRE? Or its PPTP? I think you should google for "ip_nat_pptp" iptables module. I think every modern linux firewall support it.

Try smoothwall.

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smoothwall does in fact support it. after using them both pfSense seems like a better product, but until they fix this either in the BSD kernel or elsewhere, im stuck with smoothwall. – Devnull Mar 27 '10 at 5:15

This is the limiatation of PPTP Passthrough. Sourssprite solution will work. However some people will not have a router that can terminate the VPN tunnel. What you are actually describing is VPN passthrough where the router allows outbound VPN connections. There are problems though and I know I found an article called Multiple VPN Connections – Why It Isn’t Possible which explains why this happens and ways around it. It's a good read!

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